The difference between Decent and Indecent

When used as adjectives, decent means appropriate, whereas indecent means offensive to good taste.

check bellow for the other definitions of Decent and Indecent

Decent as an adjective (obsolete):

Appropriate; suitable for the circumstances.
Decent as an adjective (of a person):

Having a suitable conformity to basic moral standards; showing integrity, fairness, or other characteristics associated with moral uprightness.
Decent as an adjective (informal):

Sufficiently clothed or dressed to be seen.

Examples:

"Are you decent? May I come in?"
Decent as an adjective:

Fair; good enough; okay.

Examples:

"He's a decent saxophonist, but probably not good enough to make a career of it."
Decent as an adjective:

Significant; substantial.

Examples:

"There are a decent number of references out there, if you can find them."
Decent as an adjective (obsolete):

Comely; shapely; well-formed.

Examples:

"A sable stole of cyprus lawn / Over thy decent shoulders drawn"

Indecent as an adjective:

offensive to good taste
Indecent as an adjective:

not in keeping with conventional moral values; improper, immodest or unseemly