Drupal Blocks list
You can see the list of existing blocks by using "Structure" -> "Block layout" menu item.
The are two types of blocks: system blocks (menu blocks, views blocks etc.) and custom blocks (you can add one or more custom blocks). If you want to display any available block, you should place the block in the region (place on the web page). Each Drupal theme provides the list of available regions.
If you want to know where regions are placed on the web page, use "Demonstrate block regions" link
In order to place block to region use "Place block" buttons or "Region" select list opposite each region.
Drupal block configuration
When you create a new custom block next configurations are availbale:
1. Block description - A brief description of your block (visible on Custom blocks library page)
2. Body - custom block has body field
3. Revision information
When you place any block to region next configurations are availbale for you:
1. Block title (visible for users above block content and on the blocks list page)
2. Display title - yes/no (visibility for users)
3. Content types - Specify content types where the block should be visible or hidden.
4. Pages - Specify pages by using their paths where the block should be visible or hidden.
5. Roles - Hide or show the block for user based on their roles
6. Region where the block should be displayed
On the blocks page next configurations are availbale for each block:
1. Enable/disable state - disable block are not available for users
2. Region where the block should be displayed