I don’t know what these things mean. I know damage linker does damage. Carry linker does damage. But what is a carry. And why do I need carry ender?
Carry means that it pushes your opponent sideways closer to the edge of the stage. It’s good for getting your opponent into a corner where they will have fewer options and certain combo setups work better. The enders also generally (but not always, like in Sadira’s case) cause a wall-splat if you’re close enough to the edge of the stage. You can also use the enders to give yourself some much needed space with the enders, particularly if you’re a character that can zone or that has reach.
My main, Aganos, is really good at all of the above. He can easily push his opponent into the corner with his natural disaster, instantly corner his opponent with his cyclopean walls, can wall-spat like nobody else (and can do even better with his character-specific wall-crashes) with multiple specials AND normals, and on top of all that has some of the longest reaching moves in the game that can go nearly full-screen. And none of that even accounts for his chunk-armor or ability to easily destroy projectiles!
This is the most basic definition. And like Geek said, they’re best used to get the opponent into the corner.
Some characters are lucky and have damage linkers that double as carry linkers, like Tusk, Sabrewulf, Riptor, Hisako, and Gargos. Plus, Omen and Riptor get some of their best damage off of their carry/wallsplat enders, and Aganos can send you into (and in special cases, through) the corner with a single well placed Ruin.