netwyman

" Port Zero " does not officially exist. It is defined as an invalid port number. But valid Internet packets can be formed and sent "over the wire" to and from "port 0" just as with any other ports. Port 0 carries special significance in network programming, particularly in the Unix OS when it comes to socket programming where the port is used to request system-allocated, dynamic ports. Port 0 is a wildcard port that tells the system to find a suitable port number. Unlike most port numbers, port 0 is a reserved port in TCP/IP networking, meaning that it should not be used in TCP or UDP messages. Network ports in TCP and UDP range from number zero up to 65535. Port numbers in the range between zero and 1023 are defined as system ports or well-known ports. The Internet Assigned Numbers Authority (IANA) maintains an official listing of the intended usage of these port numbers on the internet, and system port 0 is not to be used. How TCP/UDP Port 0

SSL Stands for "Secure Sockets Layer." SSL is a secure protocol developed for sending information securely over the Internet. Many websites use SSL for secure areas of their sites, such as user account pages and online checkout. Usually, when you are asked to "log in" on a website, the resulting page is secured by SSL. SSL encrypts the data being transmitted so that a third party cannot "eavesdrop" on the transmission and view the data being transmitted. Only the user's computer and the secure server are able to recognize the data. SSL keeps your name, address, and credit card information between you and merchant to which you are providing it. Without this kind of encryption, online shopping would be far too insecure to be practical. When you visit a Web address starting with "https," the "s" after the "http" indicates the website is secure. These websites often use SSL certificates to verify their authentic

A mail server (or email server) is a computer system that sends and receives   email . In many cases,   web servers   and mail servers are combined in a single machine. However, large   ISPs   and public email services (such as Gmail and Hotmail) may use dedicated hardware for sending and receiving email. In order for a computer system to function as a mail server, it must include mail server   software . This software allows the system administrator to create and manage email accounts for any   domains   hosted on the server. For example, if the server hosts the   domain name   "techterms.com," it can provide email accounts ending in "@techterms.com." Mail servers send and receive email using standard email   protocols . For example, the   SMTP   protocol sends messages and handles outgoing mail requests. The   IMAP   and   POP3   protocols receive messages and are used to process incoming mail. When you   log on   to a mail server using a   webmail   inter