The difference between Contingent and Impossible

When used as nouns, contingent means an event which may or may not happen, whereas impossible means an impossibility.

When used as adjectives, contingent means possible or liable, but not certain to occur, whereas impossible means not possible.

check bellow for the other definitions of Contingent and Impossible

Contingent as a noun:

An event which may or may not happen; that which is unforeseen, undetermined, or dependent on something future; a contingency.
Contingent as a noun:

That which falls to one in a division or apportionment among a number; a suitable share; proportion.
Contingent as a noun (military):

A quota of troops.

Contingent as an adjective:

Possible or liable, but not certain to occur; incidental; casual.
Contingent as an adjective:

(with upon or on) Dependent on something that is undetermined or unknown.

Examples:

"The success of his undertaking is contingent upon events which he cannot control."
Contingent as an adjective:

Dependent on something that may or may not occur.

Examples:

"a contingent estate"
Contingent as an adjective:

Not logically necessarily true or false.
Contingent as an adjective:

Temporary

Examples:

"contingent labor, contingent worker"

Impossible as an adjective:

Not possible; not able to be done or happen.

Examples:

"It is difficult, if not impossible, to memorize 20,000 consecutive numbers."

"Sarah thinks that nothing is impossible because things can always somehow happen."
Impossible as an adjective (colloquial, of a person):

Very difficult to deal with.

Examples:

"You never listen to a word I say – you're impossible!"
Impossible as an adjective (math, dated):

imaginary

Examples:

"impossible quantities, or imaginary numbers"