The OS services

• The OS does the following:
• Keep the system UP & TIDY
• Grant resources to services and hardware.
• Starts the PAM or login program
• The login ask you for credentials, if you are recognized it loads one shell for you:
• A Text shell
• or
• A Graphic shell
• The OS also launches the processes given by a user to the shell.
• MALWARE usually intervene the OS!

DRIVER: Low level interface between the OS and a hardware component.

SERVICE (windows) or

DAEMON (UNIX, BSD): Software running continuously to perform repetitive OS tasks at defined times.

APPLICATIONS or UTILITIES: Programs to perform specific tasks as a response to a user request.

Notes:

EL sistema operativo hace lo siguiente:

Mantiene al sistema limpio y funcionando (excepto windows)—¡uff, borren eso! No dije nada.

Administra los recursos de los dispositivos y programas en ejecución.

Inicia el programa de ingreso de usuarios (Pam o login).

Proporciona un SHELL (texto o gráfico) para usuarios reconocidos.

Ejecuta las instrucciones dadas por el usuario al SHELL.