flow chart vs flow diagram

flow chart and flow diagram both are nouns.

Word	Noun	Adjective	Verb	Adverb
flow chart	Yes	No	No	No
flow diagram	Yes	No	No	No

As nouns, flow chart and flow diagram are synonyms defined as:

flow chart and flow diagram: a diagram of the sequence of operations in a computer program or an accounting system

Other synonyms of flow chart include flow sheet, flowchart.

flow chart (noun)	flow diagram (noun)
a diagram of the sequence of operations in a computer program or an accounting system	a diagram of the sequence of operations in a computer program or an accounting system