Generally, necklaces consist of two different parts: the chain and the pendant. For the most part, these are not connected. Typically, the pendant is free-floating and can be worked off of the chain with little effort. However, in some cases, the pendant is fixed to the chain, making it one complete piece.
Why is this?
There are several different reasons why this may be. When you fix a pendant to the chain, you situate it in the center, with the complete clasp on the opposite end of the chain.
Doing this prevents the clasp from sliding around your neck and moving to the front. This can be a source of annoyance for some, as the clasp can seem unsightly. With a fixed pendant, the clasp will only move to the front if the pendant travels completely around the neck.
It is also much easier to re-center the necklace, because you know exactly where the center of the necklace SHOULD be.
In addition, fixing the pendant to the chain creates a cohesive aesthetic that is clean and continuous, rather than having two separate pieces. If you buy a chain and pendant separately, it’s not always assured that they will look they belong on the same necklace. However, fixed pendant necklaces look very complete.