 So now, let's just go ahead and build a program. So one of the things that we're going to need, and hopefully you've already downloaded, is something known as Python. Python 3.5 is what we're using in this course. And so Python comes with an IDE known as IDLE. I've already got mine set up, but it's right here. And as soon as I click on this, I get the interpreter of IDLE. I don't actually have the fully functioning program just yet. That's actually something that we'll be doing in just a second. But what this allows me to do is this allows me to now write in commands. Say, for example, I type the word print. Print is a key word. It's a syntactical key word in Python. And so that's why you actually see it changes color a little bit. But if I open up those parentheses, you notice all of a sudden it's giving me some just a little hints as well. It's a little beneficial like that. Value. Tell me what to print. If I just say, maybe put the quotes in, and I say, hello world, and I close it. Indicates that it's closed up. But right now nothing has actually happened just yet. It's waiting for me to give it the input. I've only typed it in. As soon as I hit internal, however, take a look at that. All of a sudden, I've just told the computer, hello world. Now, like I said, this isn't actually a fully functioning program. This is just allowing me to type things in Python and it'll interpret them. If I want to take a file and then save it for later use, I actually have to come over here. File, new file. This is going to bring up a fully just blank canvas that I can work off of. Now let's say we put that same command in. As soon as I go to save it, I'll save mine to my desktop. Hello.py. Now, how do I run this? I've got my code. I've got it ready. How do I make it run? Guess what? Same as always, we have a nice little menu option here. File, run. And we can also hit the F5 key if we'd like. Oh no. Well, that's annoying. That sucks. So all of a sudden, we're introduced to something known as errors. You may have noticed that I didn't put hello world in quotes. Well, the problem is quotes are semantics or syntax of Python. And without them, Python thinks that this is a key word inside of its library. That's why print works earlier. That's why print's OK. But you notice it's highlighting this world. It's freaking out. So really understand what you're doing. So we actually have to put in those quotes. Notice it's starting to put it and make it green as to indicate this is something I do understand. And I'm going to hit Control S. That's a little keyboard shortcut so I don't have to constantly go back and forth and use the mouse. And since that's the case, I'm not even going to use the mouse. I'm going to use the handy-dandy keyboard, and there's that F5 key right there. And what we should see happen is all of a sudden the idle window, the interpreter, restarts itself, and then all of a sudden hello world appears.