At the first of the appearance of networks, LANs weren't able to meet the needs of networks for companies which have many of branches in many of countries. So, it was necessary to develop a new type of networks to connect the local networks in the different places in one of countries or connect the local networks in different countries. These types of networks are called Wide Area Networks (WAN). By using this technology, there are many of users to networks in the companies.

WAN is divided into two categories:

1- Enterprise Network.

2- Global Network.

The first type connects the local networks or the branches attributed to one company or institution in one country or many countries. The second type connects the local networks attributed to many of different institutions.

By developing networks, it was developed and improved the software to help the users. This software includes the following:

1- E-mail.

2- Scheduling.

3- Groupware.

E-mail provides the speed connection to help the users to exchange the massages which is possible attached texts, photos and files.

E-mail uses the following protocols:

1- CCITT X.400.

2- Simple Mail Transfer Protocol (SMTP).

3- Message Handling Service (MHS).

Scheduling is an electronic version from paper sheets which are used for daily, monthly and yearly planning for appointments. Also, it is used to determine the appointments and alert the user to an appointment. On the level of networks, the users of networks can know appointments of other to determine a meeting to discuss an issue.

Collective work programs use the technology of network in the connection to provide common administration for the documents by a group of the users in the different places in the real time. The user can adjust a document and also the users can participate in activating applications and the different program of the different computers.