Basic VLAN Questions

Dear all;

This is a basic question but please teach me easily asap. If possible,please teach me by using a sample network situation.

In a vlan port modes,there're three modes.

・Access Port

・Trunking Port

・General Port

I usually use Trunking port mode but I'm not sure how to use Access Port and General Port mode.

When should I use them ? What kind of network situation are they needed to use ?

Then, I can't consider the network situation that we have to use "untagged".

regards.