Elementary (adjective)

1. Of or relating to the basic principles of a subject.
2. Being at a early stage of development or learning.
3. Simple and easy to understand.

Origin:

From the latin word "elementarius", which is derived from the latin word "elementum" meaning "element, principle, rudiment".

Examples:

1. He learned the elementary principles of physics.
2. The school offers an elementary education for young children.
3. He gave an elementary explanation of the concept.
4. The book is intended for an elementary audience.
5. The company's business model is based on elementary marketing strategies.