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Kernel




The core operating system that controls processor, disk memory and other central functions
  1. What are the 4 basic functions of an operating system?
  1. Provide a user interface
  2. Manage processes
  3. Manage resources
  4. Provide security
What is a process?
A small program running on a computer that may be part of a larger program
What is a resource? (In computer terminology)
Devises connected to the CPU of a computer such as main memory, hard disk, and CD ROM drive; all running processess have to share these devices
  • What are the basic operations for creating and managing files and directories?
  • Create
  • rename
  • Modify
  • Move
  • copy
  • delete
What is attenuation?
A reduction in the strength of an electrical signal as it travels along a medium
What is error rate?
The percentage of the bits that have errors relative to the total number of the bits received in a transmission; measure of the quality of the communication.
What is Signal to Noise ratio?
The proportion of signal compared to noise, which is calculated by the formula stnR=10log10. Hight ratios indicate that the signal is stronger than the noise.
What does a Hub do?
A special type of repeater that has multiple inputs and outputs.  Each input can be switched to any of the outputs creating a point to point circuit.
What does a Router do?
Special purpose device, or computer that are used to connect two or more networks.  Directs network traffic based on its logical address.
What does a Firewall do?
A network device that protects a network by filtering out potentially harmful incoming and outgoing traffic.
What does a Switch do?
Similar to a hub with multiple inputs and outputs and a repeater.  Examines the header of a package of input and switches a point to point connection to the specified output.
What is a Coaxial wire?
Communication cable that consists of a center wire surrounded by insulation and then a grounded foil shield that is wrapped in steel or copper braid.
Twisted pair
A pair (sometimes 2 pairs) of insulated wirestwisted together and used as a transition medium in networking.
10Base5
An Ethernet networking cable made up of a thick coax cable capable of transmitting a rates up to 10 mbps


10Base 2
Same as 10Base5 except not quite as thick of a wire.
Cat5
Ethernet twisted pair.  Up to 100mbps
10BaseT
Twisted Ethernet capable of speeds up to 10Mbps
100 Base T
A fast ethernet networking cable made of 4 twisting pair wires.  100Mbps
Fiber Optic
Network cable consisting of bundles of thin glass strands surrounded by a protective plastic sheath.
What Are the types of Wireless technology?
  • Electronic signal amplified
  • radio wave manipulations
  • Signal then transmitted as electromagnetic wave.
  • Bluetooth:short range 3inch to 328 inch for keyboards, mouse, etc.
What are the names of the OSI Model?  List the 7 layers in order
Physical------cables
Datalink-----transform  data
Network-----Ip Addresses
Transport----Port
Session-------negotiation
Presentation----Translation
Application-----Web browser
What are the 3 LAN topologies?
  • Bus Topology---one line with one terminator at each end.  All are connected in a direct line fashion.
  • Star topology---Circle of Nodes with a Hub set up in the middle that connects all the nodes and the server together.
  • Ring topology---All of the Different computers connected in a circle

What is a Network Topology?
A schematic description of the arrangement of a network, including its nodes and connecting lines
What is a Protocol?
Set of rules established to facilitate communication.
HTTP
(Hypertext Transfer Protocol)-A protocol designed for transferring files(primary content)
SMTP
(Simple Mail Transfer Protocol)A TCP/IP related, high-level protocol used in sending email.
What is  FTP?
(File Transfer Protocol) A protocol designed to exchange text and bionary files via the internet.
What is TCP?
(Transmission Control Protocol) is responsible for reliablility of delivery  of data from one computer to another.
It separates data into packets, and then establishing a virtual circuit with the designation computer to transmit them.
What does IP stand for?
(Internet Protocol) The prtocol that provides the addressing and routing of internet packets from one computer to another.
DHCP
(Dynamic Host Configuration Protocol) A communication protocol that automates the assignment of IP addresses in an organization's network.
DNS
(Domain Name System)  A meathod of translating Internet domain names into IP addresses
Know the parths of the URL
Http://www.course.com/myfolder/myfile.html
What does NAT do?
(Network Address Translation)  The translation of an inside IP address to an outside IP address; NAT is often used to allow multiple computers to share on internet connection
What is XML?
(Extensible Markup Language) A markup language designed to create common information formats and share both the format and the data on the world wide web.
What 4 pieces of Information does every computer need in order to be able to attach to the Interent?
  1. Ip address
  2. Subnet Mask
  3. Dns Server
  4. Default gate
Know the top level Domain Names used on the internet...
Domain name is a name used to locate and IP Address of an organization or other entities on the world wide web.
What are the 8 Required HTML tags?
<html><Head></Head><title>
</title><Body>/<body></html>
What is a DBMS ?
(Database Management system)  A program used for managing storage, access, and modifications to a database.
What is SQL ?
(Structured Query language) A special language used to maintain the structure of a database And also modify, query, or extract information.
What is normalization?
A process of database design that structures tables to eliminate duplication and inconsistencies in the data structure.
What are Basic SQL statments and what do they do?
SELECT statement:responsible for retrieving data from one or more tables within a database.

WHERE clause: Specifies additional criteria

ORDER BY clause: Permits you to organize how the data is displayed.
How does an Array work?
A set of contiguous memory cells used for storing the same type of data. (Arranged by type and size)
How do Linked Lists work?
A data structure that uses noncontiguous memory locations to store data; each element in the linked list points to the next element in line and does no have to be contiguous to the previous element.
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