Is your system being monitored or controlled by somebody else in your absence?
Here you can find the answer.
If I want to enter in your house mutely, i need to find out open doors or windows in your house which you left open because you were unaware of the existence of that door or forgot to close that door.
In the same way our computers also has doors called PORT which it uses to connect to other computer to access service like websites, torrents download,software update services, remote connection, etc. If we are accessing any kind of service or application that uses network connection, a PORT is used for every service and application.
Here is the list of common ports and associated services:
- 20/21: File Transfer Protocol(FTP)
- 22: Secure Shell(SSH)
- 23:Telnet
- 25: Simple Mail Transfer Protocol(SMTP)
- 53: Domain Name System(DNS)
- 80: Hyper Text Transfer Protocol(HTTP)
- 110: Post Office Protocol(POP)
- 143: Internet Message Access Protocol(IMAP)
- 169: Simple Network Management Protocol(SNMP)
- 443: Hyper Text Transfer Protocol Secure(HTTPS)