What is difference between Dictionary and Array

I was just reading manual for dictionary and found has almost same expressions and the array so just curious what is the limitation of dictionary in-terms of use and how it is different from array?

A dictionnary makes a key (string) correspond to a value (like a variable sort of, but more dynamic).

An Array makes a combination of 1,2 or 3 coordinate correspond to a value.

An Array is more powerful to apply/modify things for every single value for exemple, while a dictionnary is easier to use to store values and retrieve them, or save it quickly t the webstorage.

At the end, you could theorically use only 2D or 1D arrays to do the same job, but it is not as clear.

PS: The Json format of the array is not the same as the dictionnary one.

Thanks Aphrodite that explains the way i can use both of them now on.