What's the differences between"be + Ving" and "be going to V"?

Question

konw the above two sentence patterns are quite similar, but who would like to do me a faovor to tell the exact differences ?

thanks a lot
'cause i am teaching my little kids in my class, but i am not going to give them the wrong anwser

the grammer book says both ways are okay when talking about the future or plan

thanks a lot

but the grammer books say "be + Ving " also can refer to the future action!!!

for example : what are you doing for your coming vacation?

so......when refering to the future, what the differences between the two sentences?

thanks

Answer 1

1. be + -ing (Present Progressive): refers to an action that is going on at the moment of speaking. Give examples by referring to what some of your students are doing:
Kaleb is talking to Cynthia. How about you, Lis? What are you doing?

2. be + going to + V (Near Future): since it refers to the future, ask them questions about what they are going to do the next day (next year, etc.);