Repeated site elements, a standard parking bay, a tree grouping, a structural bay, a unit type, don't need to be redrawn by hand every time they show up. Use the Insert Block tool (icon looks like a 3D cube outline) to stamp down an existing block wherever you need one.
Place a block
Click the Insert Block tool in the drawing toolbar.
Choose a block from the dropdown. Blocks are listed alphabetically by name. If your project has more than 8, click Show all N blocks to open the full Block Manager, where you can search by name and see a thumbnail preview of each one.
Move your mouse over the map to preview the block at the cursor.
Click and drag to rotate the block before you place it, then release to commit. Click without dragging to place it at its default rotation instead.
Hold Shift while dragging to snap the rotation to the grid. Type an exact angle instead of dragging to set it precisely. Press Esc to cancel the placement.
After you place one, the tool stays armed to place another copy of the same block. This follows the general "Stay in tool after drawing" setting, which also applies to every other draw-bar tool.
Where blocks come from
A block only shows up in this dropdown if your project already has it. Blocks come from two places: one you build yourself from your own geometry, using Block, Edit Block, and Add to Block, or one imported from a Content Library pack that bundles blocks.
See Edit and Advanced Tools for the block-creation commands.
For how a placed block relates to its definition, and how to edit one, see Edit a Block.