What is the root*.crt file for installing SSL?

Question

Apache HTTP Server

Important! Please do not throw links and do not write obvious comments. Everything that googles on the topic of installing certificates for httpS could not answer my question.
Situation: I was given 4 files:

• private.key - private key
  
• intermediate_.crt - intermediate certificate
  
• domen-wildcard_xx-xx-xxxx.crt - domain certificate (?)
  
• root_pem_geotrust_rapidssl_wildcard_1.crt - what is it?
  

What is root_pem_geotrust_rapidssl_wildcard_1.crt? And without it, everything works (without enumeration in the conf-file), but I would like specifics.

Answer 1

root is the same optional certificate as intermediate. In this case, this is the CA certificate of the center.

Answer 2

Does it suck? A description of what a certificate is, what it actually consists of, and where (except /dev/ass) it is inserted - did you get it? Ay-ay ... Google "asymmetric cryptography" ...
domen-xx...xx.crt and private.key - this is actually a certificate. Two of its components that are connected to each other and with other people's "halves" will not work. The file - domain-xx...xx.crt - is a public ( shared ) key, the file private.key is a private ( private ) key. The first one is distributed to everyone with each connection, the second one is stored as a photo of a naked girlfriend. These files are placed where they need to be placed and specified where they need to be specified.
intermediate.crt - certificate of the intermediate CA that issued the certificate directly. If you have a certificate only for Apache, without authentication - and without it everything will work. If authentication is required, this certificate is placed in the root certificate store.
root_pem-xxx...xxx.crt - root certificate of the CA that issued the certificate. Usually, the root certificates of all major CAs are already present in the system, but the CA doesn't care, it will gladly give its root certificate again - just in case. Again, this file is only needed for authentication purposes.
JFYI: Certificates are not only needed for https - that's only about 40% of their use, they are used much more widely, so the CA sends the maximum possible set of files.