Hardware and software do the donkey work of the modern world. Hardware is so expensive it is packaged up and sold as a general purpose computer. A computer is no good on its own to help someone do their work. The software is what turns a computer into a virtual beast of burden. The software is made of computer programs and data stores.
An application is software that is used for one purpose. A server is a type of application. Servers are found all over the Internet. An application that provides access to Internet resources is providing an Internet service: the application is called the server and the work it does defines the type of service. An Internet resource is information such as a document or a program contained somewhere in the Internet . Popular Internet services are e-mail and web.
Every customer has problems he needs to solve and tasks he needs help with. A customer may be persuaded to spend money on hardware and software to help him with his needs. Hardware is not created for its decorative qualities: computers are complex, temperamental and expensive. If a customer has a need for storing information he buys a computer and a database server application like MySQL. If the customer also wants to view web sites he obtains a web browser application like firefox.
A server is one type of application. The Internet is full of resources. Any software that is used by customers is a resource, such as images and documents. Resources are desired by clients. A lot of software on the Internet is designed to satisfy that desire by offering resources. An application that performs a service to clients from the Internet is called a server. The most famous Internet service application is the web server. Or possibly the e-mail server. Or the tennis server.
A server is usually included in a bigger application. MySQL and sendmail are two applications that contain servers in addition to other programs.
- The MySQL database application contains lots of mini-applications (little suites of programs) to cover different types of data store work. MySQL contains a database server, a client that a customer can use to talk to the server, utilities for an administrator, libraries for programmers and so on.
- The sendmail application is an MTA (Mail Transfer Agent). It sends e-mail across the Internet. An MTA has a lot of jobs to do so it contains mini-applications including a server, a client, a security checker and so on.
A computer built for running a server is different from a computer for the home. It tends to be a big beefy box with lots of memory, CPU and disk space and nothing fun such as a graphics card or audio speakers.
A suite of programs that makes up an application is delivered in one big archive, along with any documentation such as assembly instructions. This is called a package because it arrives in a box wrapped in brown paper stuck down with tape.
A computer. For some obscure reason, perhaps some astonishing lack of imagination or a shoddy grasp of language, the computer that a server runs on has also become known as a server. Other meanings of server, such as tennis server, are best avoided.
The servers in the LIC run on the same LAN. Database servers, application servers, LDAP servers and all the rest are found in the biz LAN in the middle of the LIC. One of the security features of the LIC is to protect this LAN. This LAN is protected from the outside world by not letting any customer go directly to it. There are LANs on the Internet side and the enterprise side of the LIC that contain web servers that act as proxies. Customers can contact the proxies and the proxies contact the applications on their behalf.
Every part of the LIC runs applications and many of these are servers.
In 1967 the IBM company announced it would no longer bundle software and hardware together. The software industry was born.
In the 1990s users of the Internet grew from a few techno-hippies to an entire world of nouvea nerds. Its popularity grew because of a holy trinity of services that these new age geeks wanted to get their hands on: e-mail, WWW and ftp. Everyone wanted to receive and send messages. Everyone wanted to read web sites. Everyone copied files to their shiny new web sites provided by their ISPs. There were many services behind the scenes making all this usage growth happen, but most nouvea nerds only noticed these three.
In 1999 the J2EE specification, a range of java-related API descriptions, was published. J2EE-compliant application servers started to appear in 2000.