History of POP
The Internet Engineering Task Force published the POP (post office protocol) in 1984. The backend developers wanted to simplify the layout, therefore it underwent two updates after that.
POP2, or the second version of POP, was created in 1985 and requires the SMTP protocol in order to push emails. Subsequently, the SMTP protocol was not necessary for POP3, or the third version of POP, which was published in 1988. POP 3, or Post Office Protocol, is also included in well-known email programmes like Outlook Express and Eudora. And the POP3 has been the current version ever since 1988.
POP Full Form
POP stands for Point of Presence (also known as Post Office Protocol).
It is a point where many devices share a connection and can communicate with each other. We can say that it is a man-made demarcation point (a point where the public network of a company ends and the private network of the customer begins for e.g. the point at which your broadband cable enters the house) between communicating entities. It basically consists of high-speed telecommunications equipment and technologies that help in bringing together people from all over the internet. Post Office Protocol is referred to as the POP protocol. SMTP is employed as a message transfer agent, as is well known. When a message is sent, SMPT is used to transfer it from the client to the server and ultimately to the server of the recipient. However, the Message Access Agent facilitates the transmission of the message from the receiving server to the host server. POP3 and IMAP are the two types of protocols that are included in the Message Access Agent.
An example of this would be the local access point that connects customers via their internet service provider (ISP) to the rest of the world. The size of an ISP can be calculated by seeing the number of POPs that the service provider has. The normal houses routers, modems, servers, switches, and other such devices that have to share data over networks all use POPs. Internet Service Providers have multiple POPs.