Do I understand correctly what is .subscribe()? (Angular8)

Does subscribe update data when there is a new change??
I saw this code (for angular material table):

        name => {
 = name;
          this.dataSource.filter = JSON.stringify(this.filterValues);

I understand from this code that each time there is a change in nameFilter variable, this information is updated in other variables/objects, does it?

Probably, can I explain that it’s like a subscription that updates me when there are new changes (so i can use the updated data)?

if you need more about this code, i copied it from here:

I so appreciate your answer and the time you spend to clarify the issue for me!

Source: Angular Questions