Whatever it is, it needs more light. If it were mine, I would cut off the branch to root it as a new plant and throw away the rest. It will always look terrible with the thin growth caused by too little light.

Maybe Echinocereus. More more sun, yes.

Here is mine.

I was just given these plants by someone who was also given the parent plant by someone who brought them from Rumania. I appreciate any input on how to treat them going forward, also name. The Echinocereus seems to have a different flower formation than my cacti.

When you suggest more sun, can I keep it outdoors in summer in direct sun all day or filtered sun ?

Bright light or full sun depending on the intensity of the summer sun where you live (too intense may burn it) and shift it into more sun over some weeks to avoid burning.

Flowers look more like Trichocereus than Echinocereus with the long trumpet shape and flowering along the stem rather than from the tip.