CDN Stands for Content Delivery Network.
A content delivery network (CDN) is a system of distributed servers (network) that deliver webpages and other Web content to a user based on the geographic locations of the user, the origin of the webpage and a content delivery server.
A content delivery network (CDN) is an interconnected system of cache servers that use geographical proximity as a criteria for delivering Web content.
In a CDN, content exists as multiple copies on strategically dispersed servers. A large CDN can have thousands of servers around the globe, making it possible for the provider to send the same content to many requesting client computing devices efficiently and reliably
Benefits of CDNs
Eliminate Pauses and Accommodate Heavy Traffic
Minimize Packet Loss
Optimize Live Delivery
Enable Linear Networks
Support Video on Demand
Disadvantages of CDNs
New Points of Failure
Geographical Choice Considerations
Content Management Problems
Lack of Direct Control
Popular CDN Providers
Some types of sites will almost always benefit from a CDN:
1)Sites streaming large video files
2)Sites which consist of mainly large media files like image sites
3)Sites which have known heavy traffic in different countries
Some sites almost never need a CDN:
1)Local business sites (restaurants, beauty parlors, etc.)
2)Sites that have their main traffic in one geographic area or region
How do you set a CDN up?
The main steps for setting up a CDN are
Signing up for a service
Know what files you are using
Getting your files to the CDN servers
Decide on how to name your urls (CNAME)
Ensuring your webpages are calling (using) the files you sent to the
It relies on a stateless, client-server, cacheable communications protocol -- and in virtually all cases, the HTTP protocol is used.
REST is often used in mobile applications, social networking Web sites, mashup tools and automated business processes. The REST style emphasizes that interactions between clients and services is enhanced by having a limited number of operations (verbs). Flexibility is provided by assigning resources (nouns) their own unique universal resource indicators (URIs).
REST involves reading a designated Web page that contains an XML file. The XML file describes and includes the desired content.
The REST architectural style describes six constraints. The six constraints are:
Code on Demand
RESTful applications use HTTP requests to post data (create and/or update), read data (e.g., make queries), and delete data. Thus, REST uses HTTP for all four CRUD (Create/Read/Update/Delete) operations.
REST is a lightweight alternative to mechanisms like RPC (Remote Procedure Calls) and Web Services (SOAP, WSDL, et al.).
REST is not a "standard". There will never be a W3C recommendataion for REST, for example. And while there are REST programming frameworks, working with REST is so simple that you can often "roll your own" with standard library features in languages like Perl, Java, or C#.
As a programming approach, REST is a lightweight alternative to Web Services and RPC.
Much like Web Services, a REST service is:
Standards-based (runs on top of HTTP), and
Can easily be used in the presence of firewalls.
Like Web Services, REST offers no built-in security features, encryption, session management, QoS guarantees, etc. But also as with Web Services, these can be added by building on top of HTTP:
For security, username/password tokens are often used.
For encryption, REST can be used on top of HTTPS (secure sockets).... etc.
Responsive Web design is an approach whereby a designer creates a Web page that “responds to” or resizes itself depending on the type of device it is being seen through. That could be an oversized desktop computer monitor, a laptop, a 10-inch tablet, a 7-inch tablet, or a 4-inch smartphone screen.
Responsive Web design has become one of the hottest trends in 2013. This is due in part to the growth of smartphones and other mobile devices. More people are using smaller-screen devices to view Web pages.
The purpose of responsive design is to have one site, but with different elements that respond differently when viewed on devices of different sizes.
How Does Responsive Web Design Work?
Responsive sites use fluid grids. All page elements are sized by proportion, rather than pixels.
So if you have three columns, you wouldn’t say exactly how wide each should be, but rather how wide they should be in relation to the other columns.
Column 1 should take up half the page, column 2 should take up 30%, and column 3 should take up 20%, for instance.
Media such as images is also resized relatively. That way an image can stay within its column or relative design element.
What is responsive design?
A responsive design simply means a website that has been constructed so that all of the content, images and structure of the site remains the same on any device. For example, when a user accesses a site on their desktop, they are getting the full view of the site. But when that same user goes to visit the site from their smartphone or tablet, the site will retract to fit on the smaller screen.
In other words, with a responsive website design, you don't have to have worry about having different websites for various devices or making sure that your site runs properly on a mobile device.
But there are some other really important reasons why you should make the switch to responsive design for your website.