how does people hack our accounts?

[Scizyr]

The vast majority is through disguised emails. For example, say you get notified by email when someone posts to your wall or sends you a message on Facebook. The "hacker" will send one of these notifications to your email and it will look exactly like the Facebook notification. You click on the link in the email to be taken to Facebook to view the message, before you get there though you first go to a "blank white page" that runs a script to steal your authentication for the Facebook account and sends it to the "hacker."

Another variant will take you to "Facebook" but instead of automatically signing you in from clicking the email it takes you to the Facebook sign-in page, but maybe the address bar at the top says wwwf.acebook.com but because you are on your lunch break and want to quickly read the message that HotGirl1964 sent you don't notice the fake page and willingly send your password to the "hacker" by typing your credentials into their website.

There are of course other methods but this is by far the most widely used method of "hacking" facebook/gmail/twitter/yahoo etc.

I personally don't consider this hacking. It's more a Social Engineering tactic called Phishing.

Pleasant sailing.