For example tyre size 165/75R14 has:
Tyre Width = 165 mm. This is the linear distance between the outside sidewalls of an inflated tyre without any load.
Aspect Ratio is the sidewall height as a percentage of the section width. For example, sidewall height of this tyre will
be 165 x 0.75 = 123.75 mm
Tyre type = R - Radial-ply structure
Rim Diameter = 14 inches