If there were to be an explosion in space, given that space is a vacuum and oxygen is absent, what would happen?

There are various types of explosions, but they are all characterized by a rapid expansion of volume and a rapid release of energy.

If a container bursts and its contents are under more pressure than the exterior, the container may explode.

High-speed chemical reactions that release a great deal of energy are known as chemical explosions. Some chemical explosions involve the combustion of oxygen; in these cases, atmospheric oxygen is not directly used; instead, oxygen must be mixed with the other ingredients in the proper proportions. Oxygen can cause flammable gasses to explode, and other explosives contain compounds that are rich in oxygen, like nitrates.

The mechanism of an atomic bomb is a fission chain reaction.

In the atmosphere, an explosion releases shock waves that have the potential to cause harm and sound. In space, on the other hand, an explosion causes the material to expand infinitely until it dissipates.

The absence of oxygen in space is irrelevant because, in order for explosive material to work, oxygen must be present.

The largest explosions in space are produced spontaneously by nova and supernova explosions, which happen when a large portion of a star's material undergoes fusion reactions in a brief amount of time.

There is no air to carry the pressure or sustain combustion, so explosions in space can still happen when stored energy is released—for example, from a spacecraft malfunction or an object colliding with another—but instead of producing a shockwave or fireball, the energy would be released as radiation and debris that would spread outward into space.