The blocks are saved in a file with it. This is the same file format that AutoCAD uses to save drawings. Blocks are usually saved in the same folder as the drawing in which they were created. Under Tools, Options, select the Files tab and select Support File Search Path.
Click the Add button and then Navigate and navigate to where the block drawings are located. The blocks are saved with the drawing in which they were created. If you need a block saved in another drawing, use the Design Center to locate it, and then drag and drop a copy into the drawing you are working on. Reason for the question, I have noticed that a block I make is only saved in the drawing in which it was made.
If I start a different drawing, the new block that was created in the other drawing is not available and I have to take additional steps to include the block in the new drawing. For example, you can create a dynamic block of a door of different sizes and, when used in the drawing, you can use the same dynamic block for all door sizes. Blocks are one of the most important types of objects in AutoCAD and are also used very frequently in almost all types of drawings. When using a template drawing, you'll normally only have the blocks that you're pretty sure you want to use and then insert all the other blocks as needed, that's the design manager's idea.
As I mentioned earlier, one of the main reasons for using a block is its ability to modify all of its references by modifying a single block. After selecting the drawing, select Blocks in the object type and you now have a collection of blocks that you can insert into the drawing by simply dragging and dropping. You can place block definitions in individual external drawing files using WBLOCK, but they won't appear in the list in the INSERT dialog box or in the thumbnails on the ribbon. I don't understand how the 162 blocks appear in Design Center, but they're not in the original drawing.
If you're not using blocks in your drawings, you'd better start soon because you're missing out on some of the incredible advantages of AutoCAD blocks. For example, if you use blocks to create windows on a floor plan and after adding the windows, you decide to modify the window type. If you have a lot of blocks in this list that you're not using, you can delete them with the “purge” command.