system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does our body differentiate between intention and action?

For example, thinking hard about lifting my hand Vs actually lifting my hand.
gpt
Different areas of the brain use the same neuro pathways for an action and though. 

So you have some neuro pathways for things like arm movement. Its like a telephone wire your brain can use to get information about that particular action to different parts of the brain. 

You have part of that brain that controls muscles. If this part uses that pathway, it causes the muscles to actually activate. 

Then you have another part of the brain that controls thought. If it uses the pathway, it causes you to imagine the action, without actually doing it.