vs
QUICK ANSWER
"Diagrama" is a form of "diagrama", a noun which is often translated as "diagram". "Gráfica" is a form of "gráfica", a noun which is often translated as "graph". Learn more about the difference between "diagrama" and "gráfica" below.
el diagrama()
A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
la gráfica()
A feminine noun is almost always used with feminine articles and adjectives (e.g., la mujer bonita, la luna llena).
1. (general)