What is the Application layer, level 7 of the OSI model?

About

Application layer is the 7 layer of OSI model that contains all services/application that implements a functionality above the transport layer (TCP/UDP)

They defined functionalities such as:

• data format
• security
• and more

List

The below list is non-exhaustive.

• Remote File Access / Data Transfer: transfer protocol (FTP, HTTP, …)
• Remote Directory Access:
  • DNS
  • LDAP, LDAPS,
  • DICT,
• Email server:
  • SMTP,
  • POP3, POP3S / IMAP, IMAPS
• Remote Shell Access:
  • ssh
  • Telnet