In this screencast, you're going learn all about sheets, cells, rows, and columns. Let's go ahead and open up Excel. I wanted to first explain the difference between worksheets and workbooks. A workbook is this entire file that I am working in. So up here, I have not yet saved this. This would be book 2, basic Excel files have extensions.xlsx. So this is our workbook. If you look down here on the lower left, these are sheets. So we have sheet 1 here, and we can go ahead and edit this. We can add in numbers if we'd like and so on. This is our first sheet, and if we wanted to add a second sheet, we can always go down here and we can left-click on new sheet, and that's how we can add a new sheet. In the previous screencast, I showed you how to zoom or change the magnification level, and I'm going to go ahead and do that to this sheet. So this is a second sheet. You can always rename this by right-clicking on a tab down there, and we can rename this if we like. So I could rename that for example, Data. If you'd like to hide a sheet. So sometimes I like to have information that behind the scenes that I don't want people to necessarily see. You can always right-click on that tab and you can go here to Hide. So I've hidden that sheet. Nobody knows it's there unless they right-click on any existing tab, and we do Unhide, and then it asks us for which sheet do you want to unhide. So that's how we can unhide that data sheet. Let me just go over a few things that for most people are pretty intuitive. I've just got a couple sample numbers here and I want to explain basic data entry. Again, you can enter numbers, we can enter labels, or text by just typing that in there. We will get to this in some subsequent screencast, but formulas always start with equal. So I could do equals 2 plus 3 and is calculated there. But regardless, in order for you to enter anything into a cell, you have to first click it or you have to start in a previous cell, and you can use the up and down arrows, left and right arrows to navigate to whatever cell you want to put data in or an entry in, and then you can just start typing. You can always press the Escape button if you're midway through and you decided you don't want to do that, you can press Escape and it just gets out of there and undoes everything. So once you have a cell selected, anything you enter in there is going to overwrite anything that's pre-existing. So if I go over here to the cell that has seven in it and I just type five, Enter, it's going to overwrite whatever was in there. It's going to keep the same formatting and we'll cover formatting in a later screencasts. Alternatively, I can left-click and I can go up here to the formula bar, and I can type something in there. So I could type in Hello there, and as I edit it in the formula bar, you see that it's placed in that cell. Regardless of what you put into a cell and how you start entering there, whether it be just typing into a cell or going up to the Formula Bar in order for that number, or text, or whatever you put in there to stick, you have to press Enter. So that's the way that you make it permanent. So some of that was pretty basic, and I think most people who have used Excel at least once knew about that. I'm going to explain a couple more things that are paramount to using Excel. Excel has all the sheets again, and so each of these is known as a cell. We have these column headings and these row numbers. So this cell, this is known as the active cell, that's C2. You always put the letter before the number or the column before the row. The spreadsheet is organized into columns. So if I click up here, that's the entire A column, the entire B column, and so on, and let me just show you how many different columns we have. So if I click on A1 and I do control right arrow, it goes all the way to the rightmost column in Excel, and we have XFD. To delve more into these columns, I'm going to go Control left arrow, if I scroll down here, if I press on this right arrow, and let's just go A through Z, once we get to Z, we go AA. So now A is used with A, then we'll go AB, AC, and so on. So if I go all the way to AZ, then it starts to do BA, BB, and so on. So once we get to ZZ, so here I am at ZZ, then we start over with three letters now. So AAA, and then we do AAB. We have a lot of different columns. So let's go back to cell A1, Control left arrow and now I'm back to cell A1. Same thing. We have a lot of rows here and they start with one, and if I do control down, we go all the way down to the bottom of column A and we have 1,048,576 different rows. It's unlikely that you're going to use all of those rows, but they're there if you need them. Let's do Control up, to get back to cell A1.