Characteristics of Linux

Linux is

1. Multiuser - allows number of users to work with the system at the same time
2. Multitasking - supports true preemptive multitasking. All processes independently of each other.
3. Multiprocessing - from kernel Version2.0 onwards, linux supports multiprocessor architectures. Applications are distributed across several processors.
4. Architecture Independent - runs almost on all platform that are able to process bits and bytes. examples like IBM s390, Sparc, ARM, etc
5. Demand Load Executables - only those parts of a program actually required for execution are loaded into memory.
6. Support POSIX1003.1 standard - Linux since version. onwards supports POSIX 1003.1, which defines a minimum interface to a Unix like operating system
7. Memory protected Mode - uses the processor’s memory protection mechanisms to provent the process from accessing memory allocated to the system kernel or other processes. This is for the security of the system
8. Shared Libraries - it is a collection of routines needed by a program to work. There are number of standard libraries used by more then one process at the same time. so these libraries are made to load into memory for once and all the programs can make use of it.
9. Support Various Filesystem - supports various file systems like Proc, Ext2, Ext3 and Ext4. The most commonly used file system is Ext3 and Ext4 also developed, both are journaling file systems.