Make predictions (予測) about the future.

subject + will + verb

Computers will be..., We'll go..., Smartphones will cost..., Cars won't fly...

('ll =will. won't = will not)

Will + subject + verb?

Will computers be...? Will we go...? How much will smartphones cost...? Will cars fly?

Use will to talk and ask about predictions that might happen (起こるかもしれない) and things that are not planned (予定なし)

Make predictions (予測) about the future.

subject + be verb + going to + main verb

Computers are going to be..., We're going to go..., Smartphones are going to cost..., Cars aren't going to fly...

be verb + subject + going to + main verb?

Are computers going to be...? Where are we going to go...? How much are smartphones going to cost...? Are cars going to fly?

Use going to to talk and ask about predictions that are more likely to happen (起こる可能性が高い) and things that are definitely planned (絶対に予定)