For simplicity, remember that KEYWORDS in the SQL framework are made case-insensitive by default and also for most relational databases. The computer system does not differentiate when we write SELECT or select, so we are free to write in any case. However, when it comes to writing SQL statements for enterprise applications that involve collaboration with various other teams, certain conventions are followed. The convention is to generally write SQL keywords in capital letters so that it is easy to read and understand. Even though we can technically use any case to write SQL keywords, practically, that is not done.