it means basic elements

The best techniques are the rudiments which are in 5 categories: Single Stroke Rudiments Roll Rudiments Drag Rudiments Roll Rudiments Paradiddle RudimentsYou can learn them here: http://www.vicfirth.com/education/rudiments.html

The Rudiments of English Grammar was created in 1761.

Rudiments refer to the basic building blocks or fundamentals of a skill or topic. In music, rudiments often refer to basic drumming patterns or techniques. Mastering these rudiments is key to developing more advanced skills in the specific area.

Until he masters the rudiments of chess, I wouldn't recommend that he enter the tournament.