A server, as the name describes,
is a computer that is the "service" of other machines,
and the server is the main computer that supply all kinds of information.
As we see, we have a server machine that communicates with various clients,
all claiming some kind of information.
This information can be anything from text files, video, audio, images, emails, applications, programs, database queries, etc.
Generally, server machines tend to be somewhat more powerful than a normal computer.
Especially often they have more capacity for both storage and main memory, as they have to serve many customers.
But like everything else, it depends on the needs, and we can have a lower performance server if we have few clients connected,
or if the services you want on the server does not require a great servant capacity. As an example,
we could operate a computer in our house as if it were a server, although this is not the most common.
Generally, servers are usually located in data centers of companies (buildings with large rooms dedicated to accommodate servers)