Context - This is a tool showing each occurrence of a keyword with a bit of surrounding text (the context). It can literally help you understand the context in which a certain word is being used.
Corpus term - This is a table view tool of term frequencies of the corpus. This tool shows how frequently a word is being used in a certain part of the body. It can help you understand the key content of what certain sections of the body are about.
(Source: https://voyant-tools.org/docs/#!/guide/start)
