diff --git a/src/core_plugins/kibana/public/visualize/editor/editor.js b/src/core_plugins/kibana/public/visualize/editor/editor.js
index 548aebe4684b3..422550b3cca0f 100644
--- a/src/core_plugins/kibana/public/visualize/editor/editor.js
+++ b/src/core_plugins/kibana/public/visualize/editor/editor.js
@@ -17,7 +17,6 @@ import uiRoutes from 'ui/routes';
 import uiModules from 'ui/modules';
 import editorTemplate from 'plugins/kibana/visualize/editor/editor.html';
 
-
 uiRoutes
 .when('/visualize/create', {
   template: editorTemplate,
@@ -77,16 +76,29 @@ function VisEditor($scope, $route, timefilter, AppState, $location, kbnUrl, $tim
   let stateMonitor;
   const $appStatus = this.appStatus = {};
 
+  // Retrieve the resolved SavedVis instance.
   const savedVis = $route.current.locals.savedVis;
 
+  // Instance of src/ui/public/vis/vis.js.
   const vis = savedVis.vis;
+
+  // Clone the _vis instance.
   const editableVis = vis.createEditableVis();
+
+  // We intend to keep editableVis and vis in sync with one another, so calling `requesting` on
+  // vis should call it on both.
   vis.requesting = function () {
     const requesting = editableVis.requesting;
+    // Invoking requesting() calls onRequest on each agg's type param. When a vis is marked as being
+    // requested, the bounds of that vis are updated and new data is fetched using the new bounds.
     requesting.call(vis);
+
+    // We need to keep editableVis in sync with vis.
     requesting.call(editableVis);
   };
 
+  // SearchSource is a promise-based stream of search results that can inherit from other search
+  // sources.
   const searchSource = savedVis.searchSource;
 
   $scope.topNavMenu = [{
@@ -115,6 +127,8 @@ function VisEditor($scope, $route, timefilter, AppState, $location, kbnUrl, $tim
     docTitle.change(savedVis.title);
   }
 
+  // Extract visualization state with filtered aggs. You can see these filtered aggs in the URL.
+  // Consists of things like aggs, params, listeners, title, type, etc.
   const savedVisState = vis.getState();
   const stateDefaults = {
     uiState: savedVis.uiStateJSON ? JSON.parse(savedVis.uiStateJSON) : {},
@@ -124,12 +138,17 @@ function VisEditor($scope, $route, timefilter, AppState, $location, kbnUrl, $tim
     vis: savedVisState
   };
 
+  // Instance of app_state.js.
   let $state = $scope.$state = (function initState() {
-    $state = new AppState(stateDefaults);
+    // This is used to sync visualization state with the url when `appState.save()` is called.
+    const appState = new AppState(stateDefaults);
 
-    if (!angular.equals($state.vis, savedVisState)) {
+    // The savedVis is pulled from elasticsearch, but the appState is pulled from the url, with the
+    // defaults applied. If the url was from a previous session which included modifications to the
+    // appState then they won't be equal.
+    if (!angular.equals(appState.vis, savedVisState)) {
       Promise.try(function () {
-        editableVis.setState($state.vis);
+        editableVis.setState(appState.vis);
         vis.setState(editableVis.getEnabledState());
       })
       .catch(courier.redirectWhenMissing({
@@ -137,7 +156,7 @@ function VisEditor($scope, $route, timefilter, AppState, $location, kbnUrl, $tim
       }));
     }
 
-    return $state;
+    return appState;
   }());
 
   function init() {
@@ -148,10 +167,16 @@ function VisEditor($scope, $route, timefilter, AppState, $location, kbnUrl, $tim
     $scope.indexPattern = vis.indexPattern;
     $scope.editableVis = editableVis;
     $scope.state = $state;
+
+    // Create a PersistedState instance.
     $scope.uiState = $state.makeStateful('uiState');
     $scope.appStatus = $appStatus;
 
+    // Associate PersistedState instance with the Vis instance, so that
+    // `uiStateVal` can be called on it. Currently this is only used to extract
+    // map-specific information (e.g. mapZoom, mapCenter).
     vis.setUiState($scope.uiState);
+
     $scope.timefilter = timefilter;
     $scope.opts = _.pick($scope, 'doSave', 'savedVis', 'shareData', 'timefilter');
 
@@ -258,6 +283,9 @@ function VisEditor($scope, $route, timefilter, AppState, $location, kbnUrl, $tim
     kbnUrl.change('/visualize', {});
   };
 
+  /**
+   * Called when the user clicks "Save" button.
+   */
   $scope.doSave = function () {
     savedVis.id = savedVis.title;
     // vis.title was not bound and it's needed to reflect title into visState
diff --git a/src/core_plugins/kibana/public/visualize/saved_visualizations/_saved_vis.js b/src/core_plugins/kibana/public/visualize/saved_visualizations/_saved_vis.js
index 20ab2138469b7..0bf171cd90333 100644
--- a/src/core_plugins/kibana/public/visualize/saved_visualizations/_saved_vis.js
+++ b/src/core_plugins/kibana/public/visualize/saved_visualizations/_saved_vis.js
@@ -1,6 +1,15 @@
+/**
+ * @name SavedVis
+ *
+ * @extends SavedObject.
+ *
+ * NOTE: It's a type of SavedObject, but specific to visualizations.
+ */
+
 import _ from 'lodash';
 import VisProvider from 'ui/vis';
 import uiModules from 'ui/modules';
+
 uiModules
 .get('app/visualize')
 .factory('SavedVis', function (config, $injector, courier, Promise, savedSearches, Private, Notifier) {
diff --git a/src/ui/public/courier/data_source/_doc_send_to_es.js b/src/ui/public/courier/data_source/_doc_send_to_es.js
index 5cc07f9e0425e..f7191b03100a9 100644
--- a/src/ui/public/courier/data_source/_doc_send_to_es.js
+++ b/src/ui/public/courier/data_source/_doc_send_to_es.js
@@ -1,3 +1,10 @@
+/**
+ * @name _doc_send_to_es
+ *
+ * NOTE: Depends upon the es object to make ES requests, and also interacts
+ * with courier objects.
+ */
+
 import _ from 'lodash';
 
 import errors from 'ui/errors';
diff --git a/src/ui/public/courier/data_source/doc_source.js b/src/ui/public/courier/data_source/doc_source.js
index 67d6de7e9e6b5..80be1cf7b6095 100644
--- a/src/ui/public/courier/data_source/doc_source.js
+++ b/src/ui/public/courier/data_source/doc_source.js
@@ -1,3 +1,13 @@
+/**
+ * @name DocSource
+ *
+ * NOTE: This class is tightly coupled with _doc_send_to_es. Its primary
+ * methods (`doUpdate`, `doIndex`, `doCreate`) are all proxies for methods
+ * exposed by _doc_send_to_es (`update`, `index`, `create`). These methods are
+ * called with DocSource as the context. When called, they depend on “private”
+ * DocSource methods within their execution.
+ */
+
 import _ from 'lodash';
 
 import 'ui/es';
diff --git a/src/ui/public/courier/data_source/search_source.js b/src/ui/public/courier/data_source/search_source.js
index fa15f248c92a0..109cca094ca55 100644
--- a/src/ui/public/courier/data_source/search_source.js
+++ b/src/ui/public/courier/data_source/search_source.js
@@ -1,3 +1,55 @@
+/**
+ * @name SearchSource
+ *
+ * @description A promise-based stream of search results that can inherit from other search sources.
+ *
+ * Because filters/queries in Kibana have different levels of persistence and come from different
+ * places, it is important to keep track of where filters come from for when they are saved back to
+ * the savedObject store in the Kibana index. To do this, we create trees of searchSource objects
+ * that can have associated query parameters (index, query, filter, etc) which can also inherit from
+ * other searchSource objects.
+ *
+ * At query time, all of the searchSource objects that have subscribers are "flattened", at which
+ * point the query params from the searchSource are collected while traversing up the inheritance
+ * chain. At each link in the chain a decision about how to merge the query params is made until a
+ * single set of query parameters is created for each active searchSource (a searchSource with
+ * subscribers).
+ *
+ * That set of query parameters is then sent to elasticsearch. This is how the filter hierarchy
+ * works in Kibana.
+ *
+ * Visualize, starting from a new search:
+ *
+ *  - the `savedVis.searchSource` is set as the `appSearchSource`.
+ *  - The `savedVis.searchSource` would normally inherit from the `appSearchSource`, but now it is
+ *    upgraded to inherit from the `rootSearchSource`.
+ *  - Any interaction with the visualization will still apply filters to the `appSearchSource`, so
+ *    they will be stored directly on the `savedVis.searchSource`.
+ *  - Any interaction with the time filter will be written to the `rootSearchSource`, so those
+ *    filters will not be saved by the `savedVis`.
+ *  - When the `savedVis` is saved to elasticsearch, it takes with it all the filters that are
+ *    defined on it directly, but none of the ones that it inherits from other places.
+ *
+ * Visualize, starting from an existing search:
+ *
+ *  - The `savedVis` loads the `savedSearch` on which it is built.
+ *  - The `savedVis.searchSource` is set to inherit from the `saveSearch.searchSource` and set as
+ *    the `appSearchSource`.
+ *  - The `savedSearch.searchSource`, is set to inherit from the `rootSearchSource`.
+ *  - Then the `savedVis` is written to elasticsearch it will be flattened and only include the
+ *    filters created in the visualize application and will reconnect the filters from the
+ *    `savedSearch` at runtime to prevent losing the relationship
+ *
+ * Dashboard search sources:
+ *
+ *  - Each panel in a dashboard has a search source.
+ *  - The `savedDashboard` also has a searchsource, and it is set as the `appSearchSource`.
+ *  - Each panel's search source inherits from the `appSearchSource`, meaning that they inherit from
+ *    the dashboard search source.
+ *  - When a filter is added to the search box, or via a visualization, it is written to the
+ *    `appSearchSource`.
+ */
+
 import _ from 'lodash';
 
 import NormalizeSortRequestProvider from './_normalize_sort_request';
diff --git a/src/ui/public/courier/saved_object/saved_object.js b/src/ui/public/courier/saved_object/saved_object.js
index 5c32ccac9064c..8cfe0fe1bb39f 100644
--- a/src/ui/public/courier/saved_object/saved_object.js
+++ b/src/ui/public/courier/saved_object/saved_object.js
@@ -1,3 +1,14 @@
+/**
+ * @name SavedObject
+ *
+ * NOTE: SavedObject seems to track a reference to an object in ES,
+ * and surface methods for CRUD functionality (save and delete). This seems
+ * similar to how Backbone Models work.
+ *
+ * This class seems to interface with ES primarily through the es Angular
+ * service and a DocSource instance.
+ */
+
 import angular from 'angular';
 import _ from 'lodash';
 
diff --git a/src/ui/public/es.js b/src/ui/public/es.js
index dfbceaeec2b45..def095dc08b41 100644
--- a/src/ui/public/es.js
+++ b/src/ui/public/es.js
@@ -1,3 +1,10 @@
+/**
+ * @name es
+ *
+ * @description This is the result of calling esFactory. esFactory is exposed by the
+ * elasticsearch.angular.js client.
+ */
+
 import 'elasticsearch-browser';
 import _ from 'lodash';
 import uiModules from 'ui/modules';
diff --git a/src/ui/public/events.js b/src/ui/public/events.js
index 5f7a29ccf398b..1a6b5e39934dc 100644
--- a/src/ui/public/events.js
+++ b/src/ui/public/events.js
@@ -1,3 +1,9 @@
+/**
+ * @name Events
+ *
+ * @extends SimpleEmitter
+ */
+
 import _ from 'lodash';
 import Notifier from 'ui/notify/notifier';
 import SimpleEmitter from 'ui/utils/simple_emitter';
diff --git a/src/ui/public/persisted_state/persisted_state.js b/src/ui/public/persisted_state/persisted_state.js
index 3975c20c24ea6..d883732fb3a08 100644
--- a/src/ui/public/persisted_state/persisted_state.js
+++ b/src/ui/public/persisted_state/persisted_state.js
@@ -1,3 +1,9 @@
+/**
+ * @name PersistedState
+ *
+ * @extends Events
+ */
+
 import _ from 'lodash';
 import toPath from 'lodash/internal/toPath';
 import errors from 'ui/errors';
@@ -269,4 +275,4 @@ export default function (Private) {
   };
 
   return PersistedState;
-};
\ No newline at end of file
+};
diff --git a/src/ui/public/state_management/app_state.js b/src/ui/public/state_management/app_state.js
index c2312c5cdcffa..903071a723677 100644
--- a/src/ui/public/state_management/app_state.js
+++ b/src/ui/public/state_management/app_state.js
@@ -1,3 +1,13 @@
+/**
+ * @name AppState
+ *
+ * @extends State
+ *
+ * @description Inherits State, which inherits Events. This class seems to be
+ * concerned with mapping "props" to PersistedState instances, and surfacing the
+ * ability to destroy those mappings.
+ */
+
 import _ from 'lodash';
 import modules from 'ui/modules';
 import StateManagementStateProvider from 'ui/state_management/state';
@@ -12,7 +22,13 @@ function AppStateProvider(Private, $rootScope, $location) {
 
   _.class(AppState).inherits(State);
   function AppState(defaults) {
+    // Initialize persistedStates. This object maps "prop" names to
+    // PersistedState instances. These are used to make properties "stateful".
     persistedStates = {};
+
+    // Initialize eventUnsubscribers. These will be called in `destroy`, to
+    // remove handlers for the 'change' and 'fetch_with_changes' events which
+    // are dispatched via the rootScope.
     eventUnsubscribers = [];
 
     AppState.Super.call(this, urlParam, defaults);
@@ -28,6 +44,9 @@ function AppStateProvider(Private, $rootScope, $location) {
     _.callEach(eventUnsubscribers);
   };
 
+  /**
+   * @returns PersistedState instance.
+   */
   AppState.prototype.makeStateful = function (prop) {
     if (persistedStates[prop]) return persistedStates[prop];
     let self = this;
@@ -38,8 +57,8 @@ function AppStateProvider(Private, $rootScope, $location) {
     // update the app state when the stateful instance changes
     let updateOnChange = function () {
       let replaceState = false; // TODO: debouncing logic
-
       self[prop] = persistedStates[prop].getChanges();
+      // Save state to the URL.
       self.save(replaceState);
     };
     let handlerOnChange = (method) => persistedStates[prop][method]('change', updateOnChange);
diff --git a/src/ui/public/state_management/state.js b/src/ui/public/state_management/state.js
index 84f5f6128ca1b..5dc113ecc6faa 100644
--- a/src/ui/public/state_management/state.js
+++ b/src/ui/public/state_management/state.js
@@ -1,3 +1,11 @@
+/**
+ * @name State
+ *
+ * @extends Events
+ *
+ * @description Persists generic "state" to and reads it from the URL.
+ */
+
 import _ from 'lodash';
 import angular from 'angular';
 import rison from 'rison-node';
diff --git a/src/ui/public/vis/agg_config.js b/src/ui/public/vis/agg_config.js
index c1250db719b98..6ac5e9349fb05 100644
--- a/src/ui/public/vis/agg_config.js
+++ b/src/ui/public/vis/agg_config.js
@@ -1,3 +1,10 @@
+/**
+ * @name AggConfig
+ *
+ * @description This class represents an aggregation, which is displayed in the left-hand nav of
+ * the Visualize app.
+ */
+
 import _ from 'lodash';
 import RegistryFieldFormatsProvider from 'ui/registry/field_formats';
 export default function AggConfigFactory(Private, fieldTypeFilter) {
@@ -177,7 +184,7 @@ export default function AggConfigFactory(Private, fieldTypeFilter) {
 
   /**
    * Hook into param onRequest handling, and tell the aggConfig that it
-   * is being sent to elasticsearc.
+   * is being sent to elasticsearch.
    *
    * @return {[type]} [description]
    */
@@ -189,7 +196,7 @@ export default function AggConfigFactory(Private, fieldTypeFilter) {
   };
 
   /**
-   * Convert this aggConfig to it's dsl syntax.
+   * Convert this aggConfig to its dsl syntax.
    *
    * Adds params and adhoc subaggs to a pojo, then returns it
    *
diff --git a/src/ui/public/vis/agg_configs.js b/src/ui/public/vis/agg_configs.js
index ccacd7cafaefa..293cd2504a7fa 100644
--- a/src/ui/public/vis/agg_configs.js
+++ b/src/ui/public/vis/agg_configs.js
@@ -1,3 +1,12 @@
+/**
+ * @name AggConfig
+ *
+ * @extends IndexedArray
+ *
+ * @description A "data structure"-like class with methods for indexing and
+ * accessing instances of AggConfig.
+ */
+
 import _ from 'lodash';
 import IndexedArray from 'ui/indexed_array';
 import VisAggConfigProvider from 'ui/vis/agg_config';
diff --git a/src/ui/public/vis/vis.js b/src/ui/public/vis/vis.js
index f350c4bdbfd50..365cc8163c4a3 100644
--- a/src/ui/public/vis/vis.js
+++ b/src/ui/public/vis/vis.js
@@ -1,3 +1,13 @@
+/**
+ * @name Vis
+ *
+ * @description This class consists of aggs, params, listeners, title, and type.
+ *  - Aggs: Instances of AggConfig.
+ *  - Params: The settings in the Options tab.
+ *
+ * Not to be confused with vislib/vis.js.
+ */
+
 import _ from 'lodash';
 import AggTypesIndexProvider from 'ui/agg_types/index';
 import RegistryVisTypesProvider from 'ui/registry/vis_types';
@@ -24,7 +34,6 @@ export default function VisFactory(Notifier, Private) {
 
     this.indexPattern = indexPattern;
 
-    // http://aphyr.com/data/posts/317/state.gif
     this.setState(state);
     this.setUiState(uiState);
   }
@@ -36,6 +45,8 @@ export default function VisFactory(Notifier, Private) {
 
     let schemas = type.schemas;
 
+    // This was put in place to do migrations at runtime. It's used to support people who had saved
+    // visualizations during the 4.0 betas.
     let aggs = _.transform(oldState, function (newConfigs, oldConfigs, oldGroupName) {
       let schema = schemas.all.byName[oldGroupName];
 
@@ -119,6 +130,7 @@ export default function VisFactory(Notifier, Private) {
   };
 
   Vis.prototype.requesting = function () {
+    // Invoke requesting() on each agg. Aggs is an instance of AggConfigs.
     _.invoke(this.aggs.getRequestAggs(), 'requesting');
   };
 
@@ -149,6 +161,11 @@ export default function VisFactory(Notifier, Private) {
   Vis.prototype.getUiState = function () {
     return this.__uiState;
   };
+
+  /**
+   * Currently this is only used to extract map-specific information
+   * (e.g. mapZoom, mapCenter).
+   */
   Vis.prototype.uiStateVal = function (key, val) {
     if (this.hasUiState()) {
       if (_.isUndefined(val)) {