Blocks are compound objects that are commonly used for symbols, parts, detail views, and title blocks. 
  
 
		A block is one or more objects combined to create a single object. The following are some examples of blocks inserted into drawings. 
		
 
		
 
		 Using blocks provides the following advantages: 
		
 
		- You can ensure uniformity between identical copies of furniture, fixtures, parts, symbols, and title blocks in drawings. 
		  
 
- You can insert, rotate, scale, move, and copy blocks much faster than operating on selections of individual geometric objects. 
		  
 
- If you edit or redefine a block definition, all block references in that drawing are updated automatically. 
		  
 
- You can include data such as part numbers, costs, service dates, and performance values to blocks. The data is stored in special objects called 
			 block attributes. 
		  
 
- You can reduce the file size of a drawing by inserting multiple block references instead of duplicating object geometry. 
		  
 
		Tip:  With online access, you can download AutoCAD drawing files from the web sites of commercial vendors and suppliers. This option can save you a significant amount of time, but check to make sure that these drawings are drawn correctly and to scale.