 So, this is going to be a quick tutorial. Again, I'm putting out a number of videos each week. There should be a playlist. There should be an annotation on the screen or in the description of this video to the full playlist and these are hopefully going to be very short videos and you can actually check the playlist to see everything. Last few weeks, we talked about what a shell is. Now, there's different types of shells. Today we're actually going to start working in the shell. The first command you're probably going to want to learn is the echo command. Pretty much every shell has the echo command and you can type something like echo hello and it'll echo hello. I can say echo hello world and that's great. In many cases, you don't need quotation marks but it's a good habit to get into so you really should echo and then quotations say hello world. Now there are also, you could also do single quotes like this. It's an apostrophe as well on your keyboard and it does the same thing, seems to do the same thing in this particular instance. There is a difference though where the single quotes here is more of a literal of what you're typing where the double quotations or standard quotations, you can have special characters in there that do certain things. So for example, I can say echo hello world and I can be excited about and put in some exclamation marks and it acts kind of funny. Let's try that again. Echo hello world and we'll try two exclamation marks, same thing here. So why is it doing that? And if I was to echo it like this, hello, one exclamation mark, it works but if I do two, it prints out a bunch of other stuff. So what is going on here and now that I did that, it can do the same two quotation marks or with quotation marks and it's printing out a whole bunch of stuff. What is going on here? Well, again, there are special characters, exclamation marks are one of them. If you do two exclamation marks, it actually prints out what your last command was. So when you're saying echo hello exclamation mark, exclamation mark, with or without the quotes, it's saying echo out the word hello and then whatever the previous command was. So that's why we're getting echo, hello, echo, and we're just compounding it because we keep doing it. So how do you use the exclamation marks? Well, one way would be to put the single quotes because now it's saying ignore those special characters, use them as exclamation marks. How else could you do it? Well you should be able to do quotations and then some backslashes, backslash with regular quotes, backslash is a special character saying ignore the next character as a special character displayed as a regular character. So why would you do one over the other? Well let's say you want to have quotation marks inside your sentence. So I can say, let's say he said comma hello, it's like obviously this is going to cause some problems when we go to do that where we're losing our quotation marks there. I could backslash these out and I get my quotation marks in my output or I can use single quotes out here, does the same thing. But again, if you throw in with this, don't forget to, if you're doing this you'll have a whole bunch of backslashes there. So you might go okay, so this is obviously a much cleaner way of doing it but then again lots of times you may want to use special characters especially when it comes to variables which we'll get into in a future video. So another example would be let's say I want to say echo he said comma it's a good day and oh and then I forgot to close my outside quotes or something, see it gets confusing so you need to pay attention to what you're doing. So here I can either backslash out those or if I was to use a single quote on the outside instead of backslashing that I would backslash this and I still did something wrong. So as you can see it can get confusing, try not to let it confuse you. I wanted to point these out though, in most cases you'll be fine except for when you want to put things together like that and saying double quotes, still not seeing what I'm doing wrong here but echo hello world. So again I'm trying to show you something simple but show you some problems again too. I hope I didn't complicate it yet. Most of you probably already know the echo command but I wanted to go over the difference between single and double quotes and how to backslash out special characters when you need to. So obviously this one worked and I'm still looking at this not seeing what I did wrong. If you know what I did wrong there and I'll sure I'll figure it out as soon as I stop recording the video be sure to comment below and let me know. Thanks for watching. This is the echo command. Be sure to check out the full playlist, link in the description or annotation on the screen if I remember to do that. Thanks for watching and as always have a great day.