Cost Price - precise definition

Hello I have a question regarding the term "cost price." When I create a counting Journal in Dynamics 365 for F&O, there is a tab called "Lines Detail" -> if I open it I can see the field "cost price." Usually I thought this represents the value of our Item which we have bought (so it corresponds to the price of the product receipt). But that is not true of course, since the cost price refers to the price of the released product (in the modul Product Information Management) under the manage cost tab. My question is what does cost price" means specifically? Is it the cost we have to pay in order to hold Item X in the inventory? It would be great if someone could help me, because I was Looking for a Definition and explanation, but I could not find something.