The difference between Glossology and Glottology

When used as nouns, glossology means the science of language, whereas glottology means the science of tongues or languages.

check bellow for the other definitions of Glossology and Glottology

Glossology as a noun:

The science of language; linguistics.
Glossology as a noun (botany):

The naming of parts of plants.
Glossology as a noun (chiefly, lexicography):

The definition and explanation of terms in constructing a glossary.
Glossology as a noun (medicine):

The diagnosis of disease by examination of the tongue.