Many are related to security and some to Internet Explorer problems.

You may get at least 200 MB worth, over 300 for 64-bit versions.

My old Dell 32-bit Vostro 410 didn't get scabies and die from it so far and webmail is behaving again in IE 11 so I don't have to necessarily browse it in Firefox.

Speaking of Firefox, 61.0.1 is out in 32 and 64-bit versions and 62 is in beta testing, don't forget to upgrade if you haven't set to do so automatically, use the hamburger menu and drop down to Help, choose About Firefox and the info window will start the updating or tell you it's current. Restart the browser (no computer restart is required).