Allocatable Vs Pointer

Hello Whether 'Allocatable' and 'Pointer' can be mutually used. I understand Pointer denotes to the memory address only, but Allocatable allocates the physical memory to contain the values. WIth pointer definition, where the contents (user_defined values) goes.

I also noticed that there no difference between these two under the following situation. In

Module M1

contains
subroutine passtoSub(s)
real, pointer :: s(:)

s(1) = 10.0
!assign values here
end subroutine passtoSub

end module 

program main
use M1
real , allocatable,save :: myarray(:)

allocate myarray(10)

call passtoSub(myarray)

print*, (myarray(I),I=1,ubound(myarray,1))

end program main

This works fine, but how the datas of myarray in Main and Subroutine handled as this code serves the purpose. Just want to understand more on this.

In addition, are they use the same memory locations and addresses in both cases? Like Main allocates a different memory while pass it on to Subroutine, Subroutine pointer takes a different memory but the lifespan of the pointer only at Subroutine level, once control comes back to Main, it released?

Appreciate for clarifications..

Thank you