Double value monospace

[RinatValiullov]

I was confused a little about this double value of monospace when noticed it at first glance. Can anyone explain why it exists here?

59 |/** 
60 | * 1. Correct the inheritance and scaling of font size in all browsers.
61 | * 2. Correct the odd `em` font sizing in all browsers.
62 | */
63 |  
64 | pre {
65 | font-family: monospace, monospace; /* 1 */
66 | font-size: 1em; /* 2 */
67 | }

Origin:
base.css - line 65

[RinatValiullov]

Ok, I found a good explanation Please explain monospace, monospace one more time :) about this hack in source normalize.css

So will close this issue as duplicate many-many times.