In C computer programming language, the backslash (leans backwards) means that the character following the backslash needs to be treated a special way. For example, a means alarm or beep, or v means vertical tab. It’s interesting to note there are many terms for the backslash such as backslant, backwhack, escape, reverse slant, whack and more.
A forward slash or more commonly just called slash (leans forward) is used to separate parts in a web address, such as this website: proprofs.com/discuss/... I don’t really know how a slash is used in C programming but I do know in some programming languages a slash is used as a dividing symbol.