Google Analytics is a system to measure your website viewers. In the earlier days of the World Wide Web sites used to have counters on them that showed how many visitors the site had or the number of hits (how many times the page had been opened. You seldom see that on sites anymore. They gave us very limited information on the web users.
Google Analytics has moved the counting of your visitors on a web site into a marketing research tool. With Google Analytics as a very simple setup, you can count your visitors, know where they came from, what time of day how many people are viewing your site, etc.
With that information you can now realize which pages on your site people use more and also if a it is marketing site, set specials depending on when people use the site. You can go further with Google Analytics and find what site they came from to your site (was it a Google search, typing in the address directly, coming from other sites (and which ones), responding to ads, or email). You can also see what route they go thru your site, what page they may last visit (if it was not doing a sell or requesting information, the page may confuse them and they stop there).
You can also find out how many are returning to your site and determine for those who buy, if you are selling something, where they started and what route was it to purchase. You can also track users on all this data by whether they use your web pages or a mobile app.
I recently completed a short course by Google on Google Analytic Fundamentals and am using them more in my web sites. Google Analytics is a free service of Google and you can go and start using by going to http://www.google.com/analytics
As a follow-up on an article I did on cryptolocker a few weeks ago:
Do not click on links or attachments in emails that claim to be of voice mails for you or appearing to be from package companies like UPS and FedEx about packages not delivered. Cryptolocker is now being distributed as they links and attachments.. This vicious virus that encrypts all the data files (.doc, .jpg, .xls, etc) and offers to unlock if you wire them $300 and which may or may not work. There is no way to otherwise decrypt them and make usable again.