LINUX OPERATING SYSTEM FUNDAMENTAL

• Kernel: It is the core of the OS which interacts with the underlying hardware.
• Linux is an open source OS whose kernel was developed by Linus and other functionality was developed many enthusiastics.
• Windows and macOS are proprietary OS whose code are hidden for bussiness perspective.
• Linux Distribution is an operating system are built on top of the open source code of Linux
• Two major wellknown and active Linux Distribution are RPM based Distribution and Debian Based Distribution based on the ways they are installed
• RPM(Red Hat Package Manager) based Distribution:
  1. RedHat
  2. Fedora
  3. CentOs
  4. Oracle OS
  5. Mageia
• Debian Package Based Distribution:
  1. Debian
  2. ubuntu
  3. elementary
• Linux is popular on Server Systems due to its usage as
  1. Web Servers(Apache and Nginx) which can be installed on Windows and macOS
  2. Email servers(postfix and sendmail)
  3. Database Servers(postgresql, mysql and mariadb)
  4. Virtualisation(Xen and KVM): Creating Virtual machine
  5. Container Platform(Docker and Kubernetes)
• Linux is also used as a Mobile Platform(Android)
• Linux used for Cloud Infrastructure(AWS, Azure and Google Cloud)

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DATABASE

• A database is an organised collection of data
• Types of Database
  1. Embedded Database and Flat Files
     • Berkely DB, CSV file, JSON file, XML file:
  2. Relational Database
  3. NoSQL Database
  4. Distributed Database
     • Data is distributed over a cluster of databases to avail the data easily.
     • Data are replicated over multiple servers
     • Load Balancer is used to get data over multiple servers