"Hits" is a useless statistic though it is used by many to promote sites. A hit is counted every time one file is accessed on your server, whether it be a page, an image, a program, js file, css file etc. Complex or highly visual pages with lots of js or small images therefore will get 40 "hits" for a page with say a css, 2 js's and 36 images. A page with no images or scripts, gets "1" hit.
The "log lingo" really depends on the logging package you are using. Most give good help files. General definitions are poor because there is limited agreement over how to define things like unique visitors, visits, etc.
A "visit" depends on how your web log program defines it, but I'm fairly sure your program is referring to one IP that visits you site. Whether they visit 1 page or many, they are just counted as 1 visit.
A "page view" is a useful index. Just looking at how many times people visited an actual page.
"Unique visitors" is another way to measure. That is also defined by your sofwtare but is meant to count a visitor only once if they visit multiple times. Some popular software defines a unique visitor as an IP that visits more than say 30 minutes apart. They are therefore assumed to be different as an IP visit may in fact be a different person accessing from the same IP.
Don't overinterpret your logs. It is really hard to know what a visitor is due to the fact that logs only log computers that visit your site - not human beings! Some ISP's alocated different IP's every time a dial up user connects etc...
We use logs a lot, but not in an absolute sense. We use them mainly to find referring pages/sites, SE hits, in a relative sense to see how each page is performing over time, and what pages are getting more hits than others.
There are better ways to measure web site performance such as number of subscriptions to your newsletter, number of signs up, number of sales, number of bookmarks, number of emails you get from the site, number of guest book sign ups etc. etc. etc. These are what we call "outcome variables" rather than "process variables" which your log represents.
Also don't forget that not every page view is an actual read by a human being. Most of our page hits are from search engine spiders, email harvesters, page change checkers, and heaps of automated services where the page is not actually "read" by a human. Yet another reason why you should ignore boasts of "hits" that websites claim in their advertising spiels.
Of course using cookies and other technology can give you a better idea of visits.
(Edited for grammar and spelling since Brett made this a hot topic :))