In AutoCAD, a block is a collection of objects that are combined into a single named object. The following
are some sample blocks at various scales.

Some of these blocks are realistic representations of objects, some are symbols,
and one of them is an architectural title block for a D-size drawing.

Insert a Block

Typically, each of these blocks is an individual drawing file, perhaps saved in a
folder with similar drawing files. When you need to insert one into your current drawing
file, you use the INSERT command (or enter I in the Command window).

The first time you insert the drawing as a block, you need to click Browse to locate
the drawing file. Make sure you organize your blocks into easy-to-find folders.

Once inserted, the block definition is stored in your current drawing. From then on, you can choose it from the Name
drop-down list without needing to click the Browse button.

Notice that when you insert a block, it is attached to your cursor at the point indicated.
This location is called the insertion point. By default, the insertion point is the
origin point (0,0) of the original drawing.

After inserting the block, you can select it and a grip appears. You can easily move
and rotate this block using this grip.

In the following example, a drawing file is inserted into the current drawing to
provide a standard detail view.

Create a Block Definition

Instead of creating a drawing file to be inserted as a block, you might want to create
a block definition directly in your current drawing. Use this method if you do not
plan to insert the block into any other drawing. In that case, use the BLOCK command
to create the block definition.

For example, this is how you could create a module for a cubicle design.

1. Create the objects for the block.
2. Start the BLOCK command.
3. Enter a name for the block, in this case Quad-Cube.
4. Select the objects that you created for the block (click 1 and 2).
5. Specify the block insertion point.

You can enter the information for steps 3, 4, and 5 into the Block Definition dialog
box in any order.

After creating the block definition, you can insert, copy, and rotate the block as
needed.

Using the EXPLODE command, you can explode a block back to its component objects if
you need to make changes. In the illustration below, the cubicle on the right was
exploded and modified.

In this example, you would probably create a new block definition from the objects
in the exploded block.