while I am learning how to implement OOPS concepts (abstraction, inheritance, overloading ...ect) in vb.net , I am reading UML books.

Where does the concepts UML fit in OOP? Like say "Composition" relationship between classess. According to the definition of composition if there is parent-child relationship. Container class and contained class.
say for example "Bank" is a class and "Bank Account" is another class. with out "Bank" class there can't be a "Bank Account" class and there can be many "Bank account" classess for each "Bank class". Is there a specific way we can implement the various relationships of classess in VB.NET? where does the INHERITANCE fit into all the UML concepts? Pls help me out here ..thank you