Map ip to domain instead of host

Simple question:
How do you make it so a user can type yahoo.com into their browser
instead of www.yahoo.com and get to the same destination?

I tried to search for an answer to this but frankly I can't seem to work
out a set of keywords that points me to an answer.

I tried variations along these lines but couldn't get it to work:
fake.com domain
In db.zoneinfo
x IN A 10.10.10.1
y IN A 10.10.10.2
;10.10.10.3 now resolved in db.webpage
Z IN A 10.10.10.4

In db.webpage
fake.com. IN A 10.10.10.3
www IN CNAME fake.com.

But of course I'm not doing this correctly or else it would be working.
Can anyone help me out here?

-Mike