IMAP and bearheads
HTTP, not FTP, FTP allows you to download files, HTTP allows you to view.
The File Transfer Protocol is a standard network protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client-server model architecture using separate control and data connections between the client and the server
The Server Message Block (SMB) is a network sharing protocol that has an application-layer network protocol used for providing shared access to any file, printer, fax, and other computer miscellaneous. SMB also allows updating files on the remote server.
RDP
IMAP4 by design keeps your emails on the server. POP3 accounts can be configured to leave copies on the server.
POP is Post Office Protocol. It is a protocol used by email clients to retrieve emails from a remote server.
FTP hosts are a server on the internet that people can access with an FTP client. It allows users to easily exchange data over a fundamental network protocol.
This is called a server. Mostly called a FTP server.
file server
pop & imap
A rack or collection of hardware, the software is the component that makes it a server. What software/protocol depends on the type of server: DNS, Mail, Web servers etc.
There is no single protocol used between a server and a client; the protocol depends on what the server and client are doing and how they are currently communicating.