NLP - (Text|Token) Normalization - Case Insensitivity - lemmas
About
A normalization process remove insignificant differences between otherwise identical words to make for better searching
Would you search for déjà vu, or just for deja vu?
lemmas are normalized word forms.
Articles Related
Operation List
uppercase to lowercase
Stripping accents, diacritics and other character marking like ´, ^, and ¨. So that a search for rôle will also match role, and vice versa. It will make esta, ésta, and está all searchable as the same word
Documentation / Reference