GCSE Digital Technology - ALL TOPICS MC

GCSE Digital Technology: Measuring and Storing Digital Data

• Analogue data is continuous and used by humans, while digital data is discrete and used by computers.

• Binary digits, or bits, are the smallest pieces of data that a computer can process/store.

• Digital devices cannot process analogue information and all data needs to be converted into binary before a computer can use it.

• Examples of analogue devices include clocks and thermometers, while examples of digital devices include smartphones and digital cameras.

• Magnetic storage mediums, such as computer hard drives, use magnetizable coatings to store data, but can be less portable and more vulnerable to damage.

• Optical storage mediums, such as CDs and DVDs, use lasers to read stored data and are ideally sized for storing movies and videos.

• Solid-state storage, such as USBs and SSD drives, has no moving parts and offers faster data retrieval, but can be more expensive.

• Cloud storage stores data remotely online and can be accessed from anywhere with a network connection.

• Digital sound must be converted from analogue to digital data before it can be processed by a computer.

• An analogue to digital converter (ADC) is used to convert analogue sound waves into digital data.

• Digital images can be stored as bitmap or vector images, and compression techniques are used to reduce file size.

• Revision activities include identifying the difference between analogue and digital data, matching facts to analogue and digital devices, and understanding storage mediums and conversion processes.Understanding Digital Sound and Images

• Digital sound is produced by converting analogue sound into digital data using an analogue-to-digital converter (ADC).

• Digital sound can be edited on a computer and then converted back to analogue sound using a digital-to-analogue converter (DAC).

• Sampling is the process of taking regular measurements of sound waves and converting them into digital data.

• The quality of digital sound is determined by two factors: the sampling rate (measured in Hz) and the bit depth (number of bits per sample).

• Digital sound can be stored in uncompressed formats (such as WAV and FLAC) or compressed formats (such as MP3 and WMA).

• Uncompressed formats offer higher quality but larger file sizes, while compressed formats offer smaller file sizes but lower quality.

• Bitmap images are made up of pixels and are often larger in size, while vector images are made up of mathematical calculations and are smaller in size.

• Image resolution refers to the number of pixels in an image, with higher resolutions offering sharper images but larger file sizes.

• Image compression can be lossless (such as PNG) or lossy (such as JPEG and GIF), with the former maintaining image quality and the latter sacrificing quality for smaller file sizes.

• The system life cycle for creating a new ICT system involves stages of investigation, analysis, design, implementation, maintenance, and evaluation.

• Investigation involves methods such as questionnaires, interviews, and observing staff to identify user requirements and problems with the existing system.

• Evaluation involves determining how well the new system meets initial requirements, identifying necessary changes, and planning for continued evolution.Digital Technology Summary

• Different types of software include off-the-shelf, BPM, CRM, ERP, educational, resource management, time management, and bespoke software.

• Bespoke software is customized for a specific company's needs, but it can be expensive and time-consuming to develop.

• Anti-virus software detects virus signatures on a computer system and notifies the user to take action.

• Features of anti-virus software include secure banking, parental control, anti-phishing, VPN, anti-ransomware, support, and notifications.

• Backups can be performed using full, incremental, differential, or grandfather-father-son methods, each with advantages and disadvantages.

• USB flash drives, external hard drives, solid-state media, and cloud storage are all options for data storage, each with their own pros and cons.

• A disaster recovery plan is necessary for companies in case of system failure, and should include a recovery time objective, a recovery point objective, and regular testing and verification.

• To determine the reliability of online sources, it is important to check for facts, judgement, bias, plagiarism, recognition, correctness, and accreditation, and to use multiple trustworthy sources.

• Implementation methods for digital systems include pilot, parallel, and big bang, each with their own advantages and disadvantages.

• Marketing methods include email, advertising through websites, social media marketing, influencer marketing, data mining, customer segmentation, product recommendation, and pricing strategies.

• Monetizing content can be achieved through affiliate links or requesting donations.

• Threats to data include phishing emails, malware, social engineering, brute force attacks, data interception, and denial of service attacks, and prevention strategies include employing ethical hackers, identifying vulnerabilities, and implementing security measures.WJEC GCSE Digital Technology Revision Notes

• The concept of digital footprints and how they are used for monitoring current and prospective employees, security, and businesses.

• Notable figures in the history of computing, including Ada Lovelace, Grace Hopper, and Steve Jobs.

• Examples of industrial robots used in manufacturing, such as welding, painting, assembling, palleting, packaging, and labeling.

• The impact of robotics on society, culture, and the economy, including the loss of lower-skilled jobs and the creation of highly skilled new roles.

• The difference between industrial and autonomous robots, with the latter having the ability to make their own decisions.

• Advantages and disadvantages of autonomous cars, including fewer accidents and job losses for taxi and bus drivers.

• Social, economic, legal, and ethical impacts of autonomous cars, such as who would be at fault in the event of a crash and whether they should be programmed to protect the occupants or the most lives.

• The concept of virtual reality and its application in education, such as exploring historical sites and viewing scientific phenomena.

• Advantages and disadvantages of virtual reality, including its immersive nature and potential distraction from the main point of a lesson.

• Industries using virtual reality, such as education, military, medicine, and mental health.

• Examples of how virtual reality is being used to improve certain areas, such as training for military personnel, medical simulations, and treatment for mental health disorders.

• The use of augmented reality in navigation systems, sports broadcasting, and neurosurgery.