# Computer-aided design/AutoCAD introduction

Part of:
* Engineering and Technology
* Mechanical Engineering; Production and Design Engineering
* Computer Aided Design Course

## You will need

* AutoCAD
Depending on the capabilities of the product, AutoCAD may be presented as AutoCAD Mechanical, or AutoCAD LT, etc. which means that focus and limitations exist according to the product, for instance, AutoCAD LT has more limitations, but is less costly. There are student and teacher versions of AutoCAD.

## Before you start

Start AutoCAD and learn a little about your workplace. The appearance on your screen may vary slightly; the position of toolbars may differ and may be changed; even the icons may look different depending on the version used.

### Command line

Arguably, the Command Line is the most important part of AutoCAD. You can draw using by only entering "commands" on this line. The Command line is similar to the terminal in Unix or Windows. AutoCAD behaves similarly to these operating systems. It accepts commands and processes them. You should read Command while here. You will see what you must (or can) do to finish commands. Also errors are displayed here.
In the beginning you will see:
at the bottom of your work area indicating that AutoCAD is waiting for a command.
Tips and notes:
* When you type a command, for example line you can executing it by pressing the Enter key, but also with the Space key. Remember that Enter and Space are the same with few exceptions, like entering dimension text.
* Commands are usually complex and require more steps. You can press Ctrl+C or Escape to leave or exit the command without executing it.
* ↑↓ Up (Down) arrow will invoke previous (next) commands. This can save you typing.
* Pressing Enter when the Command prompt is displayed empty will invoke the last command, useful when you need to do something repetitively (draw several circles)
* Period is the decimal separator, comma is delimiter. 3.5 is three an half. 3,5 are X:3 Y:5 coordinates.

### Pull down menus and toolbars

Through pull-down menus and toolbars you can access almost all commands. You can type the command in command line, or click on menu item (toolbar icon) will do the "typing" for you. Menus are configurable and many AutoCAD installations have different sets of menu items. Usually installation of AutoCAD library will modify menus, or as an experienced user, you can add your own menu items and toolbar icons.

### Status Bar

Status bar buttons allows to see and change different modes of drawing such as Ortho, Osnaps, Grid, Otrack, etc. On the left side you can see current X,Y coordinates of cross-hair. Note that if you move mouse, displayed coordinates will change. Coordinates are displayed in drawing units. Note that drawing units has not physical dimension. They are not inches or millimeters, just units. You may specify later (during dimensioning and plotting) how drawing units are scaled to physical units.

### WCS (World Co-ordinate System) Icon

Icon show you which direction positive X, Y and Z go. The W means you're in the World Co-ordinate System. (Can be changed to a User Co-ordinate System.) If origin (point 0,0,0) is visible, then icon will be placed in origin. Icon may look differently according to selected view mode.

### Model and Layouts

Model tab is where you draw. You have an almost infinite area to draw and you usually see only just a section of the entire space. There are 0..n layouts, technical drawings that are representations of 3D model. Changes in 3D model are so propagated to all layouts.
* Back to CAD Course
* Next lesson (co-ordinates, lines, circles)