Add glossary with some basic DVC terminologies

src/Documentation/sidebar.json

@@ -48,6 +48,7 @@
     "name": "User Guide",
     "folder": "/static/docs/user-guide",
     "files": [
+      "glossary.md",
       "dvc-files-and-directories.md",
       "dvc-file-format.md",
       "large-dataset-optimization.md",
@@ -63,6 +64,7 @@
       "dvcignore.md"
     ],
     "labels": {
+      "glossary.md": "Glossary",
       "dvc-files-and-directories.md": "Files and Directories",
       "dvc-file-format.md": "File Format (.dvc)",
       "large-dataset-optimization.md": "Large Dataset Optimization",

static/docs/user-guide/glossary.md

@@ -0,0 +1,30 @@
+# Glossary
+
+This guide is aimed to familiarize the users with definitions to relevant DVC
+concepts and terminologies which are frequently used.
+
+## Workspace directory
+
+Also abbreviated as workspace, it is the root directory of a project where DVC
+is initialized by running `dvc init` command. Therefore, this directory will
+contain a `.dvc` directory as well.
+
+## Cache directory
+
+DVC cache is a hidden storage which is found at `.dvc/cache`. This storage is
+used to manage different versions of files which are under DVC control. For more
+information on cache, please refer to the this
+[guide](/doc/commands-reference/config#cache).
+
+## Pipeline
+
+In our documentation, it has also been referred to as a computation graph. It is
+an ordered set of some executable commands, each of them stored in a Dvcfile. To
+get familiar with its usage, please refer to this
+[tutorial](/doc/get-started/example-pipeline#example-pipelines).
+
+## DAG
+
+It is an abbreviation for Directed Acyclic Graph. DVC pipeline is also a graph
+of this type which stores a chain of commands which can be applied in a
+particular order.