Colours

JPEG (Joint Photographic Expert's Group) uses a lossy compression. If the size of the file were to be reduced using the JPEG compression, the image would loose quality. This would not be a problem in most cases however, as the human eye only sees 7 million colours, and most photographs contain more colours. JPEG would remove some redundant information in the image, giving the impression to the eye that nothing has changed. It therefore is a good compression for photographs and complex images because of the many colours they contain. There are also programs that allow the designer to specify the precise level of compression so as to ensure that the image is of a suitable quality. These were therefore used for any photographs or large pictures in the website.

GIF (Graphics Interchange Format) is not suitable for photographs and complex images due to the fact that it only uses a 256-colour palette. The compression algorithm is however lossless, so the image will not be reduced in quality by the compression. GIFF therefore was used for small images such as icons.

PNG (Portable Network Graphics) was developed in 1995. It was introduced as a response to GIF when it was declared that GIF were beginning to collect royalties for its use. PNG has a number of advantages compared to GIF. It is more compact; the opacity of the transparency can be varied, unlike GIF in which the colour is either totally transparent or opaque and PNG images render more rapidly on the screen. The major disadvantage of PNG however is that as it is a newer compression, some older browsers do not support it. Therefore, despite its advantages, it was preferred to have wider browser compatibility with regards to colours and PNG was not chosen as a suitable compression for this project.

Web Servers

A web server enables web pages to be present on the Internet. The server software will be discussed in this section.

Apache is an open source web server and can be run on Windows or Linux, although it is commonly associated with Linux. Its compatibility makes it the most widely used server on the Internet. Furthermore, Apache is scaleable so that it can be configured to run on a home or office PC.

IIS is an acronym for Internet Information Services. It is a web server that is incorporated within some Microsoft Windows operating systems. It has various benefits including reliability and security. Its disadvantages are that it is bound to Windows platforms and is expensive. It therefore was not appropriate for this project.

Databases

A database was used to achieve the dynamic content. An investigation of MYSQL and SQL Server was therefore conducted.

MYSQL was originally developed in 1979 as an open source database and is commonly used with Linux servers. It has the benefit of being fast due to the fact that it contains very little redundant code. There is also a relationship growing between MYSQL and PHP, making MYSQL support PHP in a number of ways such as PHP's function mysql query to query a MYSQL database. Its disadvantages are that it has limited support for foreign keys and does not support subqueries.

SQL Server was developed by Microsoft. It is very powerful, but is expensive to install and maintain. It is also limited to IIS. This is therefore designed for large scale databases and as this project is focussed on reserving cash flow, it is not appropriate for this project.