Understanding IP/Domain Names

What do these ones mean?

[sitemaker]

cache-los-ab01.proxy.aol.com
cache-los-ad02.proxy.aol.com
cache-los-ac06.proxy.aol.com

I ask becausethey're quite frequent in my logs this week, and the word 'proxy' raises concerns for some reason (possibly something I read somewhere once).

[larryn]

sitemaker,

[webmaster.info.aol.com...]

Your new best friend - they will explain about proxies there quite well.

Larry