IT Basics

Source: Programming Hub Android App

5 Generation of Computer

1. Vacuum tubes 1946
2. Transistors 1959
3. Integrated circuits 1965 (keyboard, monitor)
4. 4th & 5th - VLSI, ULSI. 1971

Types of Computer

1. Personal computer
2. Workstation (developers in company)
3. Mini Computer (< 500users)
4. Mainframe (company)
5. Super Computer

I/O Devices

• Input devices
  • Keyboard, mouse, touchscreen, mic
• Output devices
  • Monitor, printing, speaker

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Processing

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Memory

• Primary (Temporary)
  • RAM
  • Register
• Secondarystorage (permanent after power off)
  • Harddisk (rewrite)
  • ROM - Read only memory (no rewrite) (OS, Bios, Factory format etc )

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Program -> Compiler -> Binary code(machine language)

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Network

In 1960 LAN - Local Area Network MAN - Metropolitan Area Network WAN - Wide Area Network

Ethernet port - Uses unique MAC address (Media Access Control)

Topology

• Bus
• Star
• Ring
• Tree

Internet - Internetwork communication Message - Broken into Packets (equal size) Packets - Takes any routes available in network.  Routing - Gives direction to Packets Ip address - 122.44.78.4 Protocol standards - TCP/IP Dns - Domain name system

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Information Security

Computer has no Ethics

Threats Types

• Secrecy
• Integrity
• Availablity

Identification of users

1. Authentication
   1. Username/Password
   2. Tokens
   3. Biometric
2. Access control

Hackers

• Tricks by calling, email
• Brute force
• Common known bugs

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Content creation

Big data characteristics

• Volume
• Variety (forms & format of data)
• Velocity (quick & real time data)
• Veracity (uncertainty/quality of data)

Hadoop - Storage & Analysis of Big Data

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Dark data - useless information Internet of things - see movie Her by spike Jonze