This is just a few of the different ways that you can create shelves and shelving units to any design or concept you can imagine.
The deal is you purchase 1/2" schedule 40 steel black plumbing pipe from any hardware or big box store the length you need to achieve the vertical height you desire. You can usually get them to cut it to length and you will need one end threaded. The threaded end gets a 1/2" floor flange and this will be the base for each vertical upright.
Then you can figure out the quantity of TOP WALL MOUNTING BRACKETS you will need basically one per upright. Then you can figure out how many SHELF SUPPORT BRACKETS you will need and you can purchase these from the shop part of website
For example: The top picture would require, 4 TOP WALL MOUNTING BRACKETS and 15 SHELF SUPPORT BRACKETS. The space between wall and inside of vertical upright is 9 1/2" so that would be your max width unless you bore holes in proper locations. The boards in the photo are 12" wide, I bored 1" holes and threaded uprights through.