What will happen If i limit Restful api

On projects i'm using the solutiuon below, it allows you to response in varius types and you control on how or what you are sending. Also limit requests available and API keys.

CodeIgniter 3.x - RESTful-server
- Content-types response
- Multi language support

I'm sorry
What is this code?
$this->methods['user_post']['limit'] = 100; // 100 requests per hour per user/key
$this->methods['user_delete']['limit'] = 50; // 50 requests per hour per user/key

Is it limitation for each user or each key or each ip?