Understanding Internet and Web Services
Internet Services
The Internet offers numerous services, although in practice, we often use only one or two. Different types of Internet services arise depending on how information is accessed.
Key Internet Services
- World Wide Web (WWW): A primary service for accessing information.
- Email: Electronic mail for communication.
- Telnet: Remote connection to other computers.
- File Transfer Protocol (FTP): For transferring files.
- News: News servers for disseminating information.
- Forums and Chats: Enable conversations among multiple users.
- Videoconferencing: Conversations with images and sound.
Web Services
Web services can be defined as a set of protocols and standards used to exchange data between applications across the Web.
What are Web Services?
These services provide standard communication mechanisms between different applications, which interact to provide dynamic information to the user. To ensure interoperability and extensibility among these applications, and to allow for complex operations, a standard reference architecture is needed.
- SOAP (Simple Object Access Protocol): An XML-based protocol that allows interaction between various devices and can convey complex information.
- WSDL (Web Services Description Language): Allows a client and service to establish an agreement regarding the details of message transport and content, through a document processable by devices.
Storage of Information
Storage on the Server Itself Using the File System
This is the simplest type of storage. Information is saved on the same computer that hosts the Web application offering the service. The information is usually stored as files in directories or folders on the server computer.
Storage on the Server Using the File System and a Database
When the information to be stored is massive and requires a certain complexity of management, it’s necessary to use databases and a database management system (e.g., Oracle) to store, manage, and manipulate the information.
Example of a Dynamic Web Page Server with Database
This type of storage is often used in small and medium enterprises, small servers, and client loads with few services enabled, but with needs that require more dynamic and specific information (e.g., documents, passwords, registries, forms).
Distributed Storage Across Multiple Servers
Using specialized file systems, databases, and document databases. Depending on the functions and needs, a number of specialized servers may be used:
- File Servers: Provide files to clients.
- Database Servers: Hold large, structured data in a database.
- Web Servers: Store and provide HTML pages.
- Mail Servers: Manage the sending and receiving of email for a group of users.
- Application Servers: Dedicated to a single application, accessible by clients. These servers will have specific web applications installed and communicate with the general server using web services.
Latest Trends in Internet
Web 2.0
The term Web 2.0 was coined by Tim O’Reilly in 2004 to refer to a second generation in the history of Web technology development, based on Web Applications.
Web 2.0 encompasses user communities and a special range of services and networks. It can be understood as:
“All those Internet utilities and services that are based on a database, which can be modified by users of the service, either in content (adding, changing, or deleting information or associating data with existing information), in the form of submission, or in both content and form.” – (Ribes, 2007)
Features of Web 2.0 Technology
General characteristics of Web 2.0 include:
- The site should not act as a “walled garden”; information must be easily inserted and removed.
- Users should control their own information.
- Based exclusively on the Web: Successful Web 2.0 sites can be used entirely from a browser.
- The existence of AutoLinks is compulsory.
Other characteristics that may indicate the use of Web 2.0:
- Using XHTML with CSS.
- Using syndication (e.g., RSS).
- Support for publishing news and commentary.