No matter what CAD package you're using, drafting comes down to your ability to create and manipulate basic line work to create understandable, and accurately sized, designs. Lines are the simplest objects you can use to create your drawing, and the ones you'll use most often. I know, you're thinking: "Do I really need a lesson on how to draw a line?" Well, yes, you actually do. We all understand that a line starts at one point and ends at another, but do you know how to start it at a specific point, give it a desired length and angle or end it at a set coordinate? No worries, I'll show you how.Before we start you need to know there are two different types of "lines" when you're working in CAD: lines and polylines. We all know what a line is but a polyline requires a little explanation. A polyline is just a series of line segments that are joined together to form a single object. That may sound minor but it's one of the most important features in a CAD system. Think of it like this: if you draw a house with four walls, you can draw each side with a single line segment, no problem. When you need to move that house though, you'll need to pick each line individually (four selections) before you can do so. If you draw your house with a polyline, it is one object that you can select with a single click of the mouse. Saving three clicks on a command doesn't sound like much but in CAD, when you're running through a few thousand commands in the course of a day, those saved clicks can add up to save you hours of work!