Both refer to the future and there is a slight difference between the two though in most cases they can be used interchangeably with no difference in meaning. Even if you misuse them, a native speaker is going to understand you without any problems.
Is "with no difference in meaning" a prepositional phrase?
Is it an adjective modifying "both"?
http://www.grammar.cl/Notes/Future_Will_vs_Going.htm
Jigneshbharati Is "with no difference in meaning" a prepositional phrase? Yes. Jigneshbharati Is it an adjective modifying "both"?
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JigneshbharatiIs "with no difference in meaning" a prepositional phrase?
Yes.
JigneshbharatiIs it an adjective modifying "both"?
No, it is adverbial, modifying "used" (describes how they can be used).