Cloaking....just like putting a "cloak" on....it makes you appear to be something you're not...it can refer to many things, such as faking an IP address.
The simple answer.... Cloaking is when you deliver a different page to a user based on prior information about that user. The primary use of this is to detect the browser's user_agent which may identify if the user is a search engine bot (like googlebot) or a human If the user is a human they get content X If the user is a bot they get content y This isn't the same as putting up "hello sarah" to indicate that I'm logged in and you know me. It's when the page is way more extreme. And guess what? it'll get you banned.
I know "cloaking" to be something like using an adtracker link to cover your affiliate id. There is also a way to have your link open an affiliate page in a frame; so someone cannot strip your affiliate ID out of the link. I also know about using something called "the cloak" to hide your IP for anonymous surfing. It's great for cruising in unsavory territory as it also cuts off all cookies and pops. You can slide between the pages and not leave tracks or history. My question is, if I use an adtracker for my affiliate links on my web page, will the search engine follow through the adtracker to the destination or will it only spider up to the adtracker?
It depends how many variables this link has. If it has 2 then it's very likely it would. If it's more than 2 then it's very unlikely especially on google.