A concept is a die. What it cast is an instance.
"Number" is a concept / class / type. "47" is an instance of it.
If someone ask you to think of a number or choose a jacket in a jacket shop he is giving you a concept and a concept alone. You go fit a "concrete" object in that concept.
Note that there can be a hierarchy of concepts with only the leaves as objects.
You think in concepts. You work in objects.
In programming the whole designing phase is playing with concepts. A database table, a class, a function etc in your head is a concept. When you go in implementation phase you realize those concepts by writing code. Now you have instances / objects.
As I said above there can be a hierarchy. You make just one table and never it copies. You make copies of a class, those are instances, they are in memory, you can put data in them. You cannot put data in classes.
So, an object in OOP sense itself is a container, a concept, and data it contain is the leaf, the thing you manipulate, change and move around.
At another level of abstraction (conceptualization) objects are instances, copies of classes or whats cast by classes (dies).
The classes themselves are physical stuff casted by the die in your head which you know as concept of that class.