One of the buttons on the top of a Web browser. It allows you to “go back” to the previous web page that you were browsing.
Depending on your web browser (i.e. Internet Explorer, Mozilla Firefox, Google Chrome, etc.), the Back Button is usually located in the upper left corner area of your screen. It may not necessarily be labeled, but is probably an arrow. Most likely next to it, is another arrow that points in the opposite direction, which is the forward button (which obviously does the opposite of the back button).
Some webpages may not allow you to use the back button for security reasons and the button may be grayed out. Examples may be banking sites or gaming sites. And some sites may warn you not to hit the back button on your browser and include a back button on their page to use instead.
On the other hand, the back button can be your friend if you need to look at something on the previous page, or simply want to go back 
But, be careful, because if you were filling out a form and then hit your back button, your changes won’t be saved!
So, while the back button can be useful, handy and convenient, use some caution before clicking it!
