ERD
Entity Relationship Diagram
ELI5 — The Vibe Check
An ERD is a visual map of your database — boxes for tables, lines showing how they connect. It is the diagram you draw (or ask AI to draw) before building a database so everyone understands how data relates. Way easier than reading raw SQL.
Real Talk
An Entity Relationship Diagram visually represents the entities (tables), their attributes (columns), and the relationships between them in a database. It uses notation like crows-foot or Chen notation to show cardinality (one-to-one, one-to-many, many-to-many). ERDs are used for database design and documentation.
When You'll Hear This
"Draw an ERD before designing the schema." / "The ERD shows that users can have many orders."
Related Terms
Entity Relationship Diagram
Same as ERD — a visual picture of your database tables and how they connect. Lines between boxes show relationships.
Many-to-Many
Many-to-Many means rows on both sides can relate to many rows on the other side. Students can enroll in many courses, and courses can have many students.
Normalization
Normalization is the process of organizing your database to reduce data duplication.
One-to-Many
One-to-Many means one row in Table A can relate to many rows in Table B. One user can have many orders. One post can have many comments.
Schema
A database schema is the blueprint of your database — which tables exist, what columns they have, what types they are, and how they relate to each other.