Question

What is the difference between square bracket and curve bracket in math?

Answer 1

If you have a square bracket, the interval also contains the "head" of the interval. If it's just a round bracket, then that head is not included.  

In your examples:  

[0,5] means 0 <= x <=5  

(0,5) means 0 < x < 5  

[0,5) means 0 <= x < 5