Kinahora,

A single cylinder 2cycle engine has a power stroke every revolution. A 4cycle has one every second revolution.

In theory a 2cycle engine would have twice the potential power of a 4cycle. It doesn't.

You got to read a book about it. In 2 paragraphs in this forum, you will get very partial answers. You can get books about engines in most hobby shops and book stores.

Sincerely,