Does Tridion Docs 15 only require the installation of a "Server Certificate", or is the installation of a "Server Application Process Certificate" also necessary?

Does Tridion Docs 15 only require the installation of a "Server Certificate", or is the installation of a "Server Application Process Certificate" also necessary?

The previous certificate we purchased include both "Server Certificate" and "Server Application Process Certificate" by default.

The new certificate that we will purchase only includes the "Server Certificate". If the "Server Application Process Certificate"  is also needed, we will have to purchase it separately.

emoji