computer hardware

CPU (processor)

speed measured in cycles

multi-processor configurations

Cache

temporary holding area

Cache (L1)

• usually part of the CPU itself

• smallest and fastest to access

• restricted between 8 KB and 64 KB

Cache (L2 and L3)

• bigger and slower to access

• extra caches built between the CPU and the RAM

Non-Volatile

Storage which does not lose its contents when the power is removed.

Volatile

Temporary storage, such as in random access memory (RAM). When the power is off, the data in volatile storage is cleared out.

Client/Server

Distributed computing model through Network and Web Applications

Client

an app that requests data stored on a server

Server

a computer that awaits and responds to request for data

Thick client

Data is local, processing is local, requires/depends on local resources.

Thin Client

Data is remote, processing is done on the server (remotely), requires/depends on server resources

Operating systems

Program(s) to “Direct” the Hardware what to do

user interface

Program which manages presentation, input, and output with the user of the computer.

virtual machine

Program(s) which simulate 1 or more additional physical computers in a single machine

Licensing

You do not ever own a program, you own a license to use it:  License types are Individual, Site License, Open Source.

Firmware

Special software residing in non-volatile, read-only memory, which acts as if it is in computer’s circuitry.

BYOD (bring your own device)

A policy allowing employees to connect personally owned devices, such as tablets and smartphones, to a company network. Data security is often a concern with BYOD policies and organizations often use VLANs to isolate mobile devices.

data transmission

The transfer of data between computers or other electronic devices through a network.

analog data transmission

Continuous waves of electromagnetic energy. The intensity of the signal is measured in volts.

think: physical transmission of data through electrical volts

digtial data transmission

Can only have discrete value such as one or zero. The sequence can be transformed into digital waveform.

• have binary (0,1)

think: virtual transmission of data through binary code

physical transmission

use wire, cable and other tangible materials to send communications signals

modem

a device that translates digital (binary) to analog form, so that computers can transmit data over analog networks such as telephone and cable networks

LAN

local area network - connects a group of computers in close proximity

WAN

wide area network - connects your offices, data centers, cloud applications, and cloud storage together

VPN

• virtual private network

• Client software encrypts messages so their contents are protected from snooping

packets

Small chunks of information that have been carefully formed from larger chunks of information.

packet switching

Method of slicing digital messages into parcels (packets), sending packets along different communication paths as they become available, and then reassembling packets at destination.

IP - internet protocol

responsible for addressing and routing packets of data across the internet

TCP - transmission control protocol

provides reliable, ordered, and error-checked delivery of data between applications running on hosts in a network.

wireless LAN (WLAN)

A local area network that uses radio signals to transmit and receive data over distances of a few hundred feet

URL (uniform resource locator)

A location or address identifying where documents can be found on the Internet; a Web address

Infrastructure as a Service (Iaas)

Provides virtualized computing resources over the internet, including servers, storage, and networking. Customers have full control over their operating systems, applications, and data, and are responsible for managing and maintaining the virtualized infrastructure.

Platform as a service (PaaS)

Provides a platform for building, testing, and deploying applications without the need for managing the underlying infrastructure. The provider manages the operating system, middleware, and runtime environment, while customers focus on developing and deploying their applications.

Software as a Service (SaaS)

Provides ready-to-use software applications that are delivered over the internet. The provider manages the entire software stack, including the infrastructure, middleware, and application software, and customers only need to access and use the application through a web browser or API.

third gen (3g) networks

suitable for e-mail access, web browsing

fourth-gen (4g) networks

suitable for internet video

newest 5g networks

• download speeds up to 10-20 times faster

• better use of the radio spectrum

• enables more devices to access the internet

commodity

a good or service whose wide availability typically leads to lower customer costs