Why research?

Simple answer – find things out.
“body of knowledge” – everything we currently know.
No one knows all of the body of knowledge but some people know each aspect. e.g someone may know all about atoms and how to build machines to answer questions about them, others may know all the winners of the Eurovision Song Contest throughout the years.
Regardless of how complex and detailed or trivial, all this information makes up the body of knowledge.
The purpose of research is to expand the body of knowledge.
Generally, scientific research needs to have a purpose as it requires funding, i.e. some commercial outcome.
Humanitarian example of research could be to find a cure to an illness where many people benefit. Research still needs to be funded and this may affect how the research is used.
Research may be carried out purely for thirst of knowledge.
Results may not be something that can be currently applied but may be in the future.