how to get the number of sockets

[ESGLinux]

Hi all,
I was going to by a red hat license for a new server, an looking the note1
in this link:
https://www.redhat.com/apps/store/server/#note1

I have reallized that the important thing is the number of sockets, not the
number of cpus.

So my question is simple, how can I get the number of sockets a motherboard
has, ?(without opening it. of coures)

I have look at the /proc dir but I get only info about the cpus, not about
the sockets,

any suggestion,

Thanks in advance

ESG