The difference between Functioning and Working

When used as nouns, functioning means action of the verb function, whereas working means operation.

When used as adjectives, functioning means functional, working, whereas working means that is or are functioning.

check bellow for the other definitions of Functioning and Working

Functioning as an adjective:

Functional, working
Functioning as an adjective (euphemistic, of a person):

Mentally disabled but still able to survive in wider society.

Examples:

"Oh, he looked pretty functioning to me."

Functioning as a noun:

Action of the verb function.
Functioning as a noun:

Manner by which something functions; the workings.

Working as a noun (usually plural):

Operation; action.
Working as a noun:

Method of operation.
Working as a noun (arithmetic):

The incidental or subsidiary calculations performed in solving an overall problem.

Examples:

"Be sure to check your working."
Working as a noun:

Fermentation.
Working as a noun:

(of bodies of water) Becoming full of a vegetable substance.

Working as an adjective:

That is or are functioning.

Examples:

"a working ventilator"
Working as an adjective:

That suffices but requires additional work.

Examples:

"a working copy of the script"
Working as an adjective:

In paid employment.

Examples:

"working mothers"
Working as an adjective:

Of or relating to employment.

Examples:

"the working week"
Working as an adjective:

Enough to allow one to use something.

Examples:

"a working knowledge of computers"