Sizing the major components in a photovoltaics system

Hi Guys  the components below shows the  images of a charge  controller and a invert-er the functions of those device   differ from each other.  while one device regulate the unstable voltage coming from the solar panels the other convert DC to AC.They are consider the heart of a solar system  here is a link that explain the various type of controllers  https://youtu.be/KPZhtGLfGn4 and this link explain the different types of invert-er  https://youtu.be/75NMRgom-6w use in a solar system. my next post would be the sizing the battery bank for the solar system also