Updated: Nov 1
In other words, the present perfect continuous vs the present perfect simple.
We use I have been doing when we are talking about an activity, but it doesn't matter whether the activity has been completed. For example:
"I have been gardening all morning."
It doesn't matter whether or not all of the work in the garden has been finished.
We use I have done when an activity has been completed.
"I have planted the bulbs."
This task has been completed and all of the bulbs the gardener had are now in the ground.
These structures can also be used to ask questions to find out how long something has been happening or to find out information about completed actions.
How long....activity not yet completed (present perfect continuous)
"How long have you been working on that blog?" (the blog is not yet finished)
"How long has he been travelling in Spain?" (he is still travelling)
"How long have you been waiting for the bus?" (the bus has still not arrived)
Completed actions (present perfect simple)
"How many blog posts have you completed?"
"How many Spanish cities has he visited?"
"How many times this week has the bus been late?"