A pair of synonyms are two words that can be interchanged in a context while the initial meaning remains the same.
When writing an essay, one will often need to resort to synonyms in order to avoid repetitions or to make the text seem more professional.
Synonym finders are specialized software utilities that can be used for enhancing one's projects without needing to look up any additional tools.
These applications will typically require users to enter a source word, then will display various synonyms and users can choose the version that best suits their needs.