What does it mean on a tire example 60R?

Its part of the tyre size:

For example, say your tyre size is 195/60R16 88 S

-The 195 is the width of the tyre in mm, so its 195mm.

-The 60 is the height of the tyre side wall as a percentage of the width. This is also known as the aspect ratio.

-The R means its of a radial compound, or in other Words, its round.-The 16 is the diameter of the inner edge in inches.-88 Is the maximum load the tyre can withstand,

-and last but not least, S is the speed rating the tyre can manage.