Difference between reversible and irreversible thermodynamic process
The simplest answer in thermodynamic terms is "a reversible process is one in which the entropy generation term is zero."


  Yes, I understood that but can you explain what difference is there in the change in enthalpy, internal energy, heat, work, etc. if the process is reversible and irreversible.


For any process, all of these would be the same whether it was reversible or not. The only one that would differ would be change in entropy.