Question about vocabulary

Well, for a start, what differentiates barrier is that it's a noun and all the rest are verbs! (although both handicap and halt can be nouns as well as verbs.)

To halt something is to stop it. A halt (noun) is a brief stop or a minor railway station.

To handicap someone is to make their task more difficult by adding burdens (for example, in a race you can handicap a horse by making it carry more weight than the others). A handicap (noun) is such a burden.

To hinder or impede someone is to put obstructions in their way.

A barrier is something which blocks the road or path.

Thanks a lot:)