Terrain effects on assault

[Steel God]

For the life of me, I cannot parse this sentence out:

• If any of the attacking units consist of vehicles, then the terrain modifier of the defending hex is applied to the attacker’s assault value. Note: this modifier applies to motorized and mechanized infantry when they are in Travel Mode, but not when they are Deployed.
  

Any help?

If you assault a hex with vehicles or infantry in T mode, then the protection value of the defending hex (e.g. village -30%) is applied to your assault value ( i.e. in this example -30%).

The idea here can be summarized as assaulting into close terrain is the job for infantry