What are two major types of mutations?

There are several possible answers: silent and coding , point mutations and chromosomal changes, selected and neutral mutations, dominant and recessive mutations....

Mutations could be classified in may different ways.

Silent vs. coding: some mutations change the coding sequence of a gene so that a different protein is produced, and others do not.

Point mutations vs. chromosomal changes: A mutation could change one base into another one (A changes to C), or it could make a more drastic change in the chromosome (deleting or inserting one or more bases, reversing a chromosome section, moving a section to another chromosome or a new location in the same chromosome).

Selected vs. neutral: some mutations affect the fitness of the organism (making it better or worse) and others do not.

Dominant vs. recessive: The effect of a dominant mutation is seen if the organism has even one copy of the mutant, whereas the effect of a recessive mutation is seen only if the organism has two copies of the mutant.