Lecture Topic: Web Protocols
# Encapsulation/Decapsulation
Each layer of a network adds a header, that encapsulates the rest of the data
When a packet is decapsulated, each layer strips away its header after it is done processing

# Network Applications
Applications are *distributed* since they involve multiple end systems that exchange dat which each other

## Application Architectures
Dictates how applications interact on a network
- Client/Server architecture
	- Server: An always on host which services requests from many other hosts
		- Data is often stored on the server
		- Data centers can be used to create powerful virtual servers
	- Clients: Connect through to the server
- Peer to peer architecture
	- No always on server
	- Arbitrary end systems directly communicate
	- Peers request service from other peers and provide service in return to other peers
		- Self scalability: New peers bring new service capacity as well as new service demands
	- Peers are intermittently connected and change IP addresses (complex management)
	- Examples include BitTorrent (P2P file sharing)

# Basics of Web and HTTP
Invented by Tim Burners-Lee
Client Server model
- Client is a web browser that requests and receives, and then displays web objects
- Server is a web server that sends objects in response to 

## HTTP Request Structure
Diagram in slides (Just info from Wikipedia)

## HTTP Responses
List found in slides (just info from Wikipedia)