How can client send data to the server?
HTTP
Websockets
Why does programming in JavaScript involve the extensive use of callback
functions?
- ensures certain code doesnt execute until other code has finished
- everything works in same order
- real time applications
What is the Same Origin Policy?
restricts how a document or script loaded from one origin can interact with a resource from another origin
Purpose or Same Origin Policy
isolates potentially malicious documents
What are the advantages and disadvantages of using libraries and frameworks
for the development of web applications?
- time saving
- scalable
- robustness
X- not learning how to code
X - need to understand
What are the differences between web browsers and Node.js as JavaScript
runtime environments?
- Node.js executes server side
- browser executes client side
- Node processes the object request, browsers process response objects
Briefly describe the relationship between TCP, HTTP and WebSockets
WebSocket is a protocol providing a full duplex communication over a single TCP connection, whereas HTTP provides a half duplex, most HTTP travels over TCP
Name two different ways for maintaining state in a web-based application
cookies
web storage
What is a Content Delivery Network?
A content delivery network (CDN) is a system of distributed servers (network) that deliver pages and other web content to a user, based on the geographic locations of the user, the origin of the webpage and the content delivery server.
What is bandwidth?
maximum rate of data transfer across a given path, over a given period of time
What does it mean to say that a layer presents an abstraction of a network?
It is a generalisation of a conceptual model or algorithm, away from any specific implementation
What is a routing decision
a decision that direct network packets from their source towards their destination through forwarding decisions
What is meant by the default route for a router?
route of packet forwarding when no specific route can be determined for a given IP address
What is an authoritative name server?
An authoritative Nameserver is a nameserver (DNS Server) that holds the actual DNS records (A, CNAME, PTR, etc) for a particular domain/ address
What are checksums intended to guarantee?
If there has been any error/tampering in transmission or storage
how the use of Network Address Translation (NAT) helps us to
not run out of IP addresses
restricts the number of public address a company can use
How does Carrier Sense/Multiple Access (CSMA) manage the communication of
packets over a wireless network?
checks the traffic before sending
What is a single page application?
an app which works inside a browser and does not require page reloading during use
Describe the advantages that a single page web application model has
over the traditional client-server model for web applications.
- fast, most resources only loaded once
- no need to write code to render pages onto server
- can cache any local storage efficently
Why is Node.js so popular?
- uses javascript as its main language to build web applications
- uses V8 which can compile and run JS very fast
- single language, JS used on client and server
- easy to modifiy as bunch of small applications
Why does callback hell occur?
because the only way in JS to delay a communication so that it runs after the asynchronous call returns is to put delayed code inside a callback function
How to avoid callback hell?
- use modules
- aintain better separation of code
- use promises
2 parts of an IP?
network and host
