To understand the function of class logic, it is important to take a further look on singular terms, especially their identity. What makes an object an object as such, so how can it be identified? Thus, how can an object be differentiated between another object? In a wider sense, things can have a qualitative identity, but what is really interesting for a logician is the numerical identity which helps us to identify whether object A and B are the same objects or not. Both, qualitative identity and numerical identity have a lot of practical implications and understanding the idea of identity on a single term can help in a lot of daily situations.