Difference between Apache 1 and Apache 2

Question

What differences have branch of Apache 1 and Apache 2 ?

Advantages and disadvantages of using one or another?

Seems one of Apache 2 disadvantage is using a lot of memory, but maybe it faster at processing requests?

Most of all interesting in Apache as server for php pages (not for serving static files).

ps. maybe need compare Apache 1.3.* and Apache 2.2.*

Answer 1

Check out Overview of new features in Apache 2.0 and Upgrading to 2.0 from 1.3.