The left hemisphere is specialized in speech and language in most individuals whether right handed who are the majority as well as most of left handed too ..

As for the right hemisphere it is specialized in visuospatial functions.

And that is why left hemisphere stroke is usually associated with aphasia and right hemisphere stroke is associated with sensory hemineglect or at least sensory inattention

It also performs tasks that have to do with logic, such as in science and mathematics. On the other hand, the right hemisphere coordinates the left side of the body, and performs tasks that have do with creativity and the arts. Both hemispheres are connected by the corpus callosum and serve the body in different ways .

Cerebral Dominance. Each hemisphere of the brain is dominant for other behaviors. For example, it appears that the right brain is dominant for spatial abilities, face recognition, visual imagery and music. The left brain may be more dominant for calculations, math and logical abilities.

The theory is that people are either left-brained or right-brained, meaning that one side of their brain is dominant. If you're mostly analytical and methodical in your thinking, you're said to be left-brained. If you tend to be more creative or artistic, you're thought to be right-brained.