How do you call these plug into holes every inch frames used for this? I could use something like this for related projects.

There really is no precise name for these.

Source: A technology hoarder who has too many shelves like this full of junk.

Edit: I stand corrected by @bobson381

I have several of these under the Gorilla Rack brand name and they're sold as Industrial Shelving Units. Home Depot in the US also sells these under the Muscle Rack and Edsal brands. These shelves are good, but I caution against using them in rooms with uneven floors (i.e., basement floors) because the feet are not adjustable. The particle board shelf surfaces can also deteriorate easily in moist environments. OP's shelf is one coffee spill away from a ruined shelf. That particle board is also made with formaldehyde and water damage will release it, FYI.

I have even more Wire Rack Shelves from various brands, all mostly with interchangable parts. A major brand is Nexel. There's also a lot of good parts available through the Metro brand sold by The Container Store. I appreciate the Wire Rack Shelving for it's modularity, adjustable feet, and also the ability to use caster wheels. You can always cut your own solid shelf surface from whatever material you like. The drawback is these Wire Rack Shelves cost twice as much as the Industrial Shelving Units.

FWIW I used similar IKEA units.

Cheap and flexible, although the way they work is different (uprights have holes drilled every 2cm or so for their entire length, and you insert metal dowels at the height you need and the shelves clip into that.

What sold it for me was that the IKEA ones are made of wood, so it makes it trivially easy to modify - cut a bit out here, screw something in there etc. This made it ideal for my shed workshop build where I needed some customisations for awkward tools and I could put a workbench exactly where I want it just by screwing it in. Finally just screw the uprights together and into the wooden walls of the shed and you have a rock-solid custom-built racking system that can be reconfigured and modified easily.

Teardrop shelving! For the shape of the holes.

I'm guessing you mean the support structure for the desk and shelves, which seems to be a nicer version of something like

https://www.uline.com/Product/Detail/H-4814/Wide-Span-Storag...

or perhaps the same thing ( in several sizes ) with a coat of gloss paint

Also look into "SuperStrut" https://www.google.com/search?q=superstrut

Most common term in the US is something like Boltless Shelving, specific shelves used here were https://www.globalindustrial.com/c/storage/shelving/boltless...