Say I come visit your site on March 1. While I’m there, I visit your homepage, your about page, and your contact page. If I’m the only one to your site, here’s how your analytics profile is going to read:
Sessions: 1
Users: 1
Pageviews: 3
So I’m one user, I’ve created one session, and I’ve viewed three pages.
Now let’s pretend I come back to your site (using the same machine) on March 2. Again, I visit your homepage, about page, and contact page. Now here’s how your total will read (assuming no other activity on the site):
Sessions: 2
Users: 1
Pageviews: 6
A session “resets” by default after 30 minutes of inactivity or at the end of the calendar day. Because I came back to your site twice on different days, it’s going to register as two sessions. However, as long as I haven’t cleared my browser cookies and come back from the same device, it will still see me as one user. If however I look at your site on my desktop and then from my mobile, Google Analytics will likely show two users since (generally) it doesn’t do well tracking across devices.
Finally, pageviews just counts the number of webpages actually loaded. Every time someone loads a page on your site, it will show a pageview.
