What are hits?

I'm getting traffic thru Adwords advertising.

Google is reporting that I got 238 clicks.
On Clicky's content page, it says I got 185 hits.

When I click on the page, it says I got 153 visitors.

I know there will be discrepancies, but which one should I be comparing with the clicks from Adwords? The hits or visitors?

The two main website metrics are visits and page views.

Variations of these are unique (daily/monthly) visitors and "actions" (a Clicky "exclusive").

If you have 100 page views and 50 visits, then each visit resulted in 2 page views.

Tracking unique visitors is hard to do accurately, and so that is not the greatest metric to pay attention to.

If you sell ads by CPM, page views is what is important. If you are more into affiliate or CPC/CPA income, visits is more important to keep track of.

"Actions" equals page views plus stuff like out-clicks. It's kind of a worthless metric, but it's the closest Clicky has to page views.

"Hits" today is used like page views. In the distant past it included extra stuff like image loads and JavaScript loads and CSS file loads (except that back then nobody used CSS). Hits as a term became meaningless, since it varied wildly base on how many images you had on a page, so it went out of use. But today, with JavaScript analytics, it's come back as a simple synonym for page views.

So, I should be comparing 238 clicks with 153 visitors?
Because I think the case of someone clicking my ads twice would be rare.

When viewing your Content report, "hits" = views. So that's what you'd want to compare with the clicks that Google is reporting.

Hi, what are hits?

Hits = Page Impression
or
Hits = Frames to load on one site?

What is the definition of hits by dtrack? I don´t find anything information on this site.

hits = page impressions

How do page impressions differ from visits? Don't you have to visit the page to have an impression?

Each person who visits your site is a visitor, but they may view more than one page. There will alwoays be at least as many page views as there are visitors, but typically page views will be much higher than visitors.