What IS the Difference between Fetish and BDSM?

While fetish and BDSM may blur in people's minds due to them both frequently being seen as sexual, they are not the same thing and one can exist without the other. They can usefully be distinguished because: A fetish doesn't require interaction with a second person and can be explored or activated just by one person, BDSM is not done solo, i.e., it's always done with a second person, an action or object alone can be the object of a fetish.

In BDSM it is the engagement of two people which makes it satisfying and rewarding,

A fetish is always, by definition, sexual, and BDSM activities and relationships need not be sexual at all. Even though BDSM and fetish are distinct, in any particular BDSM activity engaged in by two people, there may be elements of both BDSM and fetish present. In fact, it may be that a top or dominant utilises a fetish of their bottom or submissive to assert power over them, thus potentially satisfying one of the motivations for BDSM.