Installing Code-Aster Salome Meca

I would like to try Code Aster or Salome Meca FEM on MS-Windows.  The problem for me is that I can't find a document that gives an overview of what each part does. 

I am used to ABAQUS that comes together with "CAE" for creating input files and visualising the results from an "Output DataBase" (ODB).  I have used the ABAQUS solver separate from CAE for some problems that it cannot create (I used Matlab to write the input file) so have no problem with the idea that different bits of code do different things.

There's a website Code_Aster for Windows (https://code-aster-windows.com/) that seems likely to be helpful, but again no straight forward explanation of what goes with what - it seems to be written for an audience that already know the system.  It seems to have downloads for Salome and Code Aster - I can't tell if one part or both are needed.  In some parts it says Code-Aster is included with Salome-Meca but on the Download page it says the .msi (Code_Aster) installation is needed in addition.

As a first application I would like to do contact mechanics modelling, including 2D (Plane strain) models.

It probably needs just a few paragraphs to make it clear - can anyone here provide them.

Regards,

Robert