Reflection of units

Some key terms that I’ve learned about for these units:

Big data is a process that allows the collection and processing of large, heterogenous volumes of data, which can be structured, semi-structured and unstructured data or video data. The goal of this big data processing is to aid today’s organisations. These organisations can capture, process, store and analyse big data to achieve a competitive advantage. Examples can include large organisations such as Google and Netflix.

Cloud Computing

Examples of 3 services provided by cloud infrastructure:

SaaS is a cloud application service which uses internet to delivery those applications that are managed by thirdparty vendors. You don’t need to download or install these the applications on your computer. Say for example, CiscoWebEx, Google Apps.

PaaS : it’s a platform as a service and allows the developers to build components to customise an application. In this service, third party vendors can manage infrastructure, like storage, network, but developers can maintain and manage the applications. Examples of PaaS is: Windows Azure, google App engine.

Infrastructure as a service: IaaS is scalable environment where the overall computing infrastructure is maintained as a self-service and on-demand basis. So, there is no need to buy software and hardware straightaway. As a result, a less powerful computer can still utilise the full power of a server without affecting its full efficiency. Examples are Microsoft Azure, Amazon web services (AWS), things like that.

Computer Networks

The main purpose of a computer network is to connect the computer resources and to allow the users to perform multiple tasks simultaneously.

A computer network is often classified as being either a personal area net-work (PAN), a local area network (LAN), a metropolitan area network (MAN), or a wide area network (WAN).

A PAN is normally used for short-range communications—typically less than a few meters—such as between a wireless headset and a smartphone, or between a wireless mouse and its PC.

Internet is an example of WAN (wide-area network), where network covers a country or even a continent. Examples of WAN is 4G and 5G that we hear a lot about.

Another way of classifying networks is based on the topology of the network, which refers to the pattern in which the machines are connected. Two of the more popular topologies are the bus, in which the machines are all connected to a common communication line called a bus and the star, in which one machine serves as a central focal point to which all the others are connected.

The distinction between the bus and the star is whether the machines in the network envision themselves as communicating directly with each other over a common bus or indirectly through an intermediary central machine.

In the Bus topology/network , the workstations can share the main cable (or the bus) for data transmission using a protocol called Carrier Sense Multiple Access (CSMA). The problem with this network is that when the main cable is broken, it affects the whole network.

Sometimes the bus network is created by running links from each computer to a central location where they are connected to a device called a hub. This hub is merely a very short bus. All it does is relay any signal it receives (with perhaps some amplification) back out to all the machines connected to it. The result is a network that looks like a star network although it operates like a bus network.

It is often possible to connect the buses to form a single long bus. This is done by means of different devices known as repeaters (most simplest device which transfers signals back and forth between the two buses), bridges (more complexly than repeaters as they send messages back and forth only when that message will reach the other side of the bus), and switches (which is a bridge with multiple connections, which allows it to connect several buses rather than just two).

The connection between networks to form an internet is handled by devices known as routers, which are special purpose computers used for forwarding messages.

The “point” at which one network is linked to an internet is often called a gateway because it serves as a passageway between the network and the outside world.

Protocols are rules by which activities are conducted on a network. The rules and procedures determine how the data will be addressed, transmitted and the rules for routing the data through a TCP/IP network.

The Internet

The most notable example of an internet is the Internet (with uppercase I). While an internet refers to any network of interconnected devices which can communicate with each other, the Internet is the global system of interconnected networks. In contrast, an intranet is a network of computers designed for a specific group of users (i.e. workers in a company).

Internet service providers are large organisations who setup, manage and maintain large networks and allow users to access, utilise and receives services. There are software and hardware involved in this process. The service providers use telephone lines, wireless hotspots or satellite to connect various networks and to let the data pass through from one network to another.

Webservers provide access to documents.

Cyber Security

Cyber security is a series of actions by which we can protect and recover network data and programs from a cyberattack. The form of attacks are malware, spam or denial of service.

Malware is a harmful software, in other words, a malicious software, that may damage your computer. A virus like spyware, worms or trojans are malicious software.

Another threat is phishing which is an email which intends to reveal company or personal information from you.

We also see denial of service or distributed denial of service in which a huge influx of services pass through the bandwidth causing this network bandwidth to collapse or to get slow not allowing targeting service to take place. There are several ways we can attempt to stop them. Maybe we can deploy a firewall or can install an anti-virus program.

Codio this week – started HTML unit on Codio and how to create a webpage

Few important things to keep in mind when coding a webpage:

Webpage always starts with the tag <html> and always has to end after everything with </html>.

The slash / is very important as you need to include it most times when you want to end something. The tag <body> is where all the displayed content is (e.g. text, images) and ends with </body>. The tag <b is when you want something written to be bold – but it ends without a slash just <b. The tag <img is when you want to insert an image. e.g. <img src = funny_man.jpg.

Learning Outcomes:

Identify and explain the architecture, structure and functionality of basic components of a computer system.

Critically appraise the emerging trends in the field, such as cloud computing, big data, cyber security, and the professional and ethical requirements for dealing with such contemporary computer-based technologies.