Briefly explain the following:

1. Application Architectures Host-Based, Client-Based, and Client-Server Architectures, Middleware architecture, 3 tier arhcitecture, N tier architecture, Choosing Architectures

2. World Wide Web How the Web Works Inside an HTTP Request & HTTP Response

3. Electronic Mail How E-Mail Works, Inside an SMTP Packet Listserv, Attachments in MIME

4. Other Applications FTP, Telnet, Instant Messaging, Videoconferencing

5. Thin and Thick clients

6. Peer to peer architecture

7. Criteria for Choosing Architecture - Infrastructure Cost Cost of servers, clients, and circuits Mainframes: very expensive; terminals, PCs: inexpensive Development Cost Mainly cost of software development Software: expensive to develop; off-the-shelf software: inexpensive Scalability Ability to increase (or decrease) in computing capacity as network demand changes Mainframes: not scalable; PCs: highly scalable

8. what is HTTP Request Message, Give example