Software divides into systems and applications software . Applications software may be:
general purpose (e.g. word processor, spreadsheet, database, etc: flexible and meant for a wide range of users);
special purpose (accounts, CAD, CAM, etc., doing just one thing but meant for many different users);
bespoke (developed for one user only).
Differences between word processor and DTP: DTP is more graphics oriented, greater control over placing of graphics and text, also has features for large-scale printing on presses e.g. CMYK colour management. DTP provides control over text to levels not found in a word processor e.g. kerning (moving letters such as V and A closer together so they overlap and there is less of a gap between them), tracking (changing the space between letters to suit the style of a document) and leading (changing the distance between lines of text). These text adjustments are measured in tiny distances e.g. points (1/72 inch) and fractions of a point or the equivalent metric distance).
Email and its advantages and disadvantages
Cheap, instantaneous (more or less), uniform cost regardless of distance, multiple destinations at once, informal, quick replies, attachments of text and multimedia files.
Can carry viruses and worms and can be a nuisance (spam).
Presentation software (PowerPoint)
Computers have many applications: accounts, payroll, orders, invoices, sales, contacts, hospitals, schools, banks, libraries, CADCAM, communications, to name but a few.
Computer control is another type of application. It involves the use of sensors to gain inputs and output deveices like motors and heating elements for outputs (controlled by actuators). Typical applications include robots, environmental monitoring (central heating, humidity in green houses), medical, manufacturing (especially chemical plants), surveillance (for security and monitoring traffic). Control systems are often embedded in everyday products e.g. washing machine, car, train, aeroplane, missile (not so everyday!).
Artificial intelligence (AI) is a type of application that is often built into other software products. e.g.Visual recognition for faces, speech, characters and car number plates. An expert system is a product which is apparently intelligent as it can answer questions on topics like medical diagnosis from a database.
Questions to ask about applications include:
What is the application for?
How are data captured and processed? (Keyed in or read by a device e.g. bar code reader in POS, sensor, magnetic ink, OCR, etc.)
What impact has the application had on people in the organisation? (Lost their jobs, made them more productive, highly skilled, motivated or demotivated)
What impact has the application had on wider society? (Easier access e.g. to library catalogue and on-line learning)
What are the security issues? (Data Protection Act, Privacy, The Computer Misuse Act (1990))
Are there other legal implications e.g. copyright, digital rights management?
Is the application robust, how does it manage failure? (Is it mission-critical? e.g. transportation system)
Does the application lead to reduced costs? (Computers are expensive to install and maintain, is the cost recovered?)
Does the application provide better information? (Better service may justify
expenditure, as in a library)