You will find wrecks, abandoned ships, and more that you can salvage. Some things that you build or find in Space Abyss can be salvaged for part of their initial resource cost
One of the easiest things to salvage is a manufacturer! They cost 20 Territe to build, and you can salvage 10 Territe from them. Right Click -> Salvage. It can be kind of hidden at the bottom of the pop-up menu since you can do so many things at a Manufacturer. Your salvaging beam will take several ticks to completely salvage the manufacturer.
As things get more advanced, salvaging does too. Lets say you find an Asteroid Ship out in the galaxy, and start salvaging it.
You will notice that when your salvaging bar completes, it doesn't immediately destroy the Asteroid Ship, but takes 10 hp away.
Each completed salvaging event takes 10 HP away from whatever is being salvaged
This is actually neat - because it means there's a lot more to salvage from this Asteroid Ship!
If you continue to salvage the asteroid, ship, you will probably sometimes fail. Some things, like Asteroid Ships, have multiple different things that can be salvaged from them. Some are easy to salvage, others are difficult. If you salvaging skill is low, you might not notice anything useful in that chunk of salvage, and miss the rare and valuable thing in that chunk.