Computer Systems Servicing

• Computer


  An electronic device that manipulates information, or "data." It can store, retrieve, and process data.
• Hardware


  Any part of your computer that has a physical structure
• Software


  Any set of instructions that tells the hardware what to do
• Desktop computer


  • Designed for use at a desk or table, typically larger and more powerful than other types of personal computers, made up of separate components
• Laptop


  • Battery or AC-powered personal computer that are more portable than desktop computers, allowing you to use them almost anywhere
• Server


  • A computer that "serves up" information to other computers on a network
• Tablet


  • A mobile computing device designed to be held in one or two hands, approximately the size of a hardcover book
• Smartphone


  • A cell phone that allows you to do more than make phone calls and send text messages, can browse the Internet and run software programs like a computer, use a touch screen to allow users to interact with them
• Mac


  The Macintosh computer was introduced in 1984, and it was the first widely sold personal computer with a Graphical User Interface, or GUI
• PC


  This type of computer began with the original IBM PC that was introduced in 1981
• System unit


  • The core of a computer system, usually a rectangular box placed on or underneath your desk
• Mouse


  • Used to interact with items on your computer screen
• Monitor


  • An output device that displays video images and text, originally comprised of a CRT (cathode ray tube) and a fluorescent screen, now using flat panel display technology
• Keyboard


  • The main way to enter information into your computer
• Speaker


  • Used to play sound, can be built into the system unit or connected with cables
• Printer


  • An external hardware output device that takes the electronic data stored on a computer or other device and generates a hard copy of it
• Motherboard


  The main circuit board within a typical desktop computer, laptop or server
• Motherboard form factors

  The specification of a motherboard – the dimensions, power supply type, location of mounting holes, number of ports on the back panel, etc.
• Central Processing Unit (CPU)


  The hardware within a computer that carries out the instructions of a computer program by performing the basic arithmetical, logical, and input/output operations of the system
• Clock speed


  A processor's rating that measures a certain number of information processed per second
• Front Side Bus (FSB)


  Serves as the processor's connection to the system memory, FSB transfer speed allows better processor performance
• Cache


  Enables the processor to speedily access recently used information
• 32-bit (x86) CPU


  An older processor structure that can process instructions less efficiently than a 64-bit processor
• 64-bit (x64) CPU


  A newer processor structure that can process instructions more efficiently than a 32-bit processor
• Random Access Memory (RAM)


  A hardware device that allows information to be stored and retrieved on a computer, RAM is a volatile memory and requires power to keep the data accessible
• Single Inline Memory Module (SIMM)


  • An older type of memory module, comes in two main sizes with 30 pins and usually holds less than 20MB of memory
• Synchronous Dynamic Random Access Memory Dual In-line Memory Modules (SDRAM DIMM)


  • A speedier type of memory module with 168 pins, ruled the computer world through most of the '90s
• Rambus Dynamic Random Access Memory (RDRAM) or RIMM


  • A super-fast, super-expensive memory created by Rambus, Inc. in the late 1990s
• Double Data Rate Synchronous Random Access Memory (DDR SDRAM)


  • A competitor to RDRAM that does some tricky piggybacking on the memory bus to speed things up dramatically
• Double Data Rate Two Synchronous Random Access Memory (DDR2 SDRAM)


  • The second generation of DDR memory that was released in September 2003, capable of operating at greater speeds than DDR, offers a greater bandwidth potential, operates on less power, and generates less heat
• Double Data Rate Three Synchronous Random Access Memory (DDR3 SDRAM)


  • A type of SDRAM released in June 2007 as the successor to DDR2, with bus clock speeds of 400 MHz up to 1066 MHz, range in size from 1 to 24 GB, and consume nearly 30% less power than their predecessors
• Double Data Rate Four Synchronous Random Access Memory (DDR4 SDRAM)


  • A type of SDRAM released in September 2014 as the successor to DDR3, with bus clock speeds that range from 800 to 1600 MHz and range in storage capacity from 4 to 128 GB per DIMM, more efficient at 1.2 V when compared to DDR3's 1.5 to 1.65 V range
• Hard disk


  A non-volatile memory hardware device that permanently stores and retrieves data on a computer, a secondary storage device that consists of one or more platters to which data is written using a magnetic head
• All computers have a hard drive installed in them, which is used to store files for the operating system, software programs, and a user's personal files. A computer cannot function without a hard drive installed, as it requires one to function properly.
• New users often confuse RAM (memory) with disk drive space.
• DDR4 SDRAM


  Double Data Rate Synchronous Random Access Memory
• DDR4 SDRAM


  • Ranges from 800 to 1600 MHz in frequency
  • Ranges from 4 to 128 GB per DIMM in storage capacity
  • More efficient at 1.2 V compared to DDR3's 1.5 to 1.65 V range
• DDR4 memory chips can only be installed on a motherboard that supports DDR4 memory and are not backward compatible with DDR3 memory slots
• Hard Disk


  A non-volatile memory hardware device that permanently stores and retrieves data on a computer
• Hard Disk


  • Consists of one or more platters to which data is written using a magnetic head
  • All computers have a hard drive installed which is used to store files for the operating system, software programs, and a user's personal files
  • A computer cannot function without a hard drive installed, as it requires one to function properly