The way I see it (the hard way), there are 3 main types of summons: Normal, Flip and Special
Normal is divided in 2 parts, which both also are divided in 2 parts:
Normal Summon
- Normal Summon
- Normal Set
Tribute Summon
- Tribute Summon
- Tribute Set
Flip is just Flip
Special is divided in 3 parts:
Special Summon
Fusion Summon
Ritual Summon
As you can see, there are 3 kinds of Normal Summon, and 2 kinds of Special Summon.
But this is very confusing, not very much people get this, but you get the point...
(it's better for non-complicate thinkers to forget this)
But of course, there also is an easy way...