Archive for the ‘Glossary’ Category

File Under: Glossary


The application program interface (API) is a set of building blocks for programmers.

APIs are made up of routines, protocols, and tools. Most operating environments provide an API so that programmers can write applications consistent with that environment. For example, developing software using the Windows API ensures that your user interface will be consistent with other Windows applications, making it easier for users to learn your new programs.

Use on the Web

Web APIs provide simple ways to interact with websites. Using an API, you can extract public data from sites like, Flickr and Digg to create mashups, reuse data or just about anything else you can imagine.

APIs are also useful for extracting your own private data from a web service so that you can back it up elsewhere or display it on another site.

When talking about APIs you’ll here the following terms quite a bit.

Common Web API Related Terms

  • Web service/API — These terms are largely interchangeable and simple refer to the ways you can interact with the data on your favorite websites.
  • Method — A method is just one aspect of an API; you might also see methods refered to a functions. For instance, if you’re interacting with Flickr, you might want to get your public photos. To do so you would use the get_user_photos method.
  • Response — The information returned by the API method that you’ve called.
  • REST — Short for Representational State Transfer. REST treats data as a web document that lives at a specific URL. REST APIs use standard HTTP requests such as GET, PUT, HEAD, DELETE and POST to interact with data.
  • XML-RPC — This older API scheme formats method calls and responses as XML documents which are sent over HTTP.
  • SOAP — Simple Object Access Protocol. A W3C standard for passing messages across the network. SOAP is the successor to XML-RPC. It’s complexity has led many to disparage SOAP and with more APIs leaning toward REST, SOAP’s future is uncertain.
  • Ajax — Asynchronous JavaScript and XML. Technically it has nothing to do with APIs, however many sites using APIs send their queries out using Ajax which is partially responsible for the popularity of JSON.
  • JSON — JavaScript Object Notation. JSON’s main advantage is that it is easy to convert from JSON to nearly any other programming language. JSON uses key-value pairs and arrays, something common to PHP, Python, Perl, Ruby and most other languages. The portability of JSON has made it an increasingly popular choice for sites developing APIs.

Popular Web APIs

File Under: Glossary


Clickthrough, or clickthrough rate (CTR), is the percentage at which viewers click on online ads and go to the advertiser’s site – whether to sign up for something, to make a purchase, or just to find out more.

The clickthrough percentage calculation is arrived at by dividing the gross number of clicks by the gross number of advertising impressions served.

File Under: Glossary

Direct Response

On the Web, direct response usually refers to a clickthrough on an ad banner.

Many advertisers will audit the effectiveness of a campaign based on the number or percentage of direct responses. While this can lead to the hard-bargain, cost-per-click deals that almost entirely ignore the branding value of web advertising, evaluating response is often the best way to an honest audit of the product, advertising message, and ad placement.

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A grayscale image uses only shades of gray to represent an image.

Black-and-white photographs can use a virtually unlimited number of shades of gray, but most computers can display only 16 or 256. To grayscale is to convert a continuous-tone image, like a black-and-white photograph, to an image made up of pixels. Grayscaling is different from dithering, which uses either black or white pixels next to one another to simulate shades of gray. In grayscaling, each individual pixel can be a different shade of gray.

File Under: Glossary


Short for internet service provider, an ISP owns and operates all of the equipment (telephony, digital cable, servers, etc.) that allow you to connect to the internet from your home or office.

Most ISPs sell access to their services for a small monthly fee, which you can access by connecting to your ISP’s computer network through a phone or cable line.