What are the differences between Unikernel and RTOS? Both are lean. Except for the fact that RTOSes are usually coded in C/C++ mostly. And Unikernel implementat

What are the differences between Unikernel and RTOS? Both are lean. Except for the fact that RTOSes are usually coded in C/C++ mostly. And Unikernel implementations are present in various languages. Other than that what is the difference? Moreover, RTOSes provide all those Real-Time guarantees.