I work in tech support, and I’m surprised by the number of times I ask someone to read me their web address, only to hear, “HTTP, colon, backslash backslash, yadda yadda yadda.” If that is, in fact, what they have written in their address bar, their browser is going nowhere fast. As it turns out, backslash and forward slash are never interchangeable.

Perhaps my experience is abnormal, but when I think about it, I NEVER hear anyone call a forward slash by its proper name. Everything is a backslash to them. Here’s how I remember it:

You are reading this text right now. You read it left to right. The sentence is moving forward as you move to the right. Now, imagine that you have a young, budding slash that hasn’t really decided his occupation, yet. He stands straight up like this –> | and hasn’t leaned either way. Now, if this strapping lad of a slash leans forward in the flow of the sentence, he is a forward slash. If he leans backward in the flow of the sentence, he is a backslash.

But more important than what you call a slash that’s already chosen his path is how use one in a situation that needs a slash. Typing in web addresses, network names, and file paths will give you errors if you use the wrong slash. If that’s not bad enough, try putting a backslash in a sentence. That no-no will throw up red flags on the Punctuation Radar of every grammar snob in a 10-mile radius.

/ is a forward slash, often just called a slash. It is used if you want to make something in a sentence as an option. For instance, “I’d like any faculty/staff/students in the area to participate.” Forward slashes are also used in web addresses (http://www.example.com/) and Linux/Mac OS X directories (/home/anthony/Desktop).

\ is a backslash (one word). It is only used in computing. It is what Windows uses in its file paths (C:\Users\anthony\Desktop) and network names (\\server\folder). It is also used in programming and scripting as an “escape,” which makes the character after it behave differently than normal.

I hope I’ve clarified this for a few people. Anything I missed? Let me know!