When you surf in Internet, all your browsing activity is stored in your computer. Besides that, many sites sends “cookies” to your computer
Fortunately, most of the modern Web Browsers have a property called “Private Browsing”. When you enable Private Browsing, your browser doesn’t logs your activity and your “cookies” dies after you close your browser, because, simply your browser doesn’t “write” that kind of data to hard disk.
Private Browsing can be enabled in that way using keyboard;
Firefox : Control+Shift+P
Google Chrome: Control+Shift+N
Internet Explorer & EDGE: Control+Shift+P
Some browsers also allow you to use that browser always in Private Browsing mode! By that way you don’t need to do something to use Private Browsing, because it is already enabled!
Notice that, enabling Private Browsing does not give you “anonymous” Browsing in Internet! If you are looking for Anonymous Browsing, you should find a good VPN service or try TOR Browser!
By the way, Opera Browser gives a free VPN access. Anonymity of a “free” VPN service can be questionable but looks better than noting!