Home Videos What is an ERD? How to Read Entity Relationship Diagrams & When to Use Them What is an ERD? How to Read Entity Relationship Diagrams & When to Use Them Jan 13, 2021 comments off Tweet on Twitter Share on Facebook Google+ Pinterest Learn the basics of entity relationship diagrams and how to read them to understand data. Want to make your own ERD? Get started with a free trial of Gliffy’s online diagramming tool at Gliffy.com.