Questions about G.Skill Aegis

Exactly, normal RAM for normal PCs. You can use this tool to read out what kind of RAM is already in the PC (select ZIP English), then you will see exactly: https://www.cpuid.com/softwares/cpu-z.html

Do the maths 2x 8GB = 16GB yes are 16GB ;-)

According to the manufacturer, this RAM is compatible with the Asrock h110m-hdv r3.0. Herstellerseite: https://www.gskill.com/qvl/165/185/1534752219/F4-2133C15S-16GIS-Qvl

Yes you are right: DDR4-2400MHz CL15-15-35 1.20V 8GB (2x4GB)