If you can't tell your back end from your e-commerce, you need our simple web design glossary!

• Accessibility - ensuring a website can be accessed in as many different ways as possible, from screen readers to mobile phones. The W3C has technical guidelines and in the UK it's a legal requirement following the DDA 1995.
• Anti-virus - software to prevent, detect and remove computer viruses and other malware. Should be installed on PCs and Macs alike!
• Apache - the most popular Web server programme used on the Internet
• App - short for application, an app is a programme which runs on your mobile, tablet or computer. Another word for software.
• Artificial Intelligence - it used to be mean computer chess players or sat navs, but the definition is shifting. Now it refers to computerised tasks that can't simply be resolved by calculations, however complex they are.
• Back end - the admin part of a website accessible only to authorised users, e.g. a content management system; see Front end
• Bounce rate - the number of visitors who leave a website after viewing just one page
• Breadcrumb trail - a series of links back up through the site structure to the home page. See Anatomy of a Web Page.
• Browser - a programme to display a Web page at a Website on the World Wide Web. Popular browsers are Chrome, Safari, Internet Explorer and Firefox.
• Cache - files like images, stylesheets and javascript files that are stored temporarily by your web browser so it's quicker to load a web page on repeated visits. You may need to clear your cache if you can't see recent changes.
• Chrome - a freeware web browser developed by Google, which currently has the largest market share
• Client-side - refers to functionality and scripts that are performed on the user's computer; see Server-side
• CMS - Content Management System, a system for amending the text on a website
• Content - words, images and downloadable files which are displayed on the pages of a website. Updated via a Content Management System.
• Cookies - small files which asks permission to be placed on your computer's hard drive. From May 2012, UK websites were required by law to comply with the EU "Cookie Law".
• CSS - Cascading Style Sheets, the main language used for styling web pages. By changing a single CSS file the colour, size or typeface of e.g. headings or links can be altered across a website.
• CSV - Comma Separate Values, a basic data file format that's can be opened in a text editor or like a spreadsheet in Microsoft Excel.
• Database - a collection of records or data stored on a Web server, common formats are MySQL and SQL Server
• Domain name - the first part of a URL, for example, iteracy.com
• Dynamic - a Web page that gives users an interactive experience
• E-commerce - buying or selling items on the Internet
• Edge - a web browser developed by Microsoft and included in Windows 10 as the default web browser
• FTP - File Transfer Protocol, a method for transferring files across the Internet
• Firefox - a freeware and open source web browser developed by Mozilla
• Flash - a plugin made by Adobe for rich functionality on Web pages. It had its heyday but since it is not supported on iPhones and iPads, it is no longer widely used.
• Flat design - a minimalist style of design popular on mobile versions of websites but might have a negative impact on usability; see Usability.
• Form - allows a user to enter data onto a web page and send it back to the Web server, which might then store the information in a database or email it to a designated address.
• Front end - the part of a website displayed to the general public; see Back end
• GIF - an older type of image file with limited colours, but capable of animation
• Hamburger menu - an icon with 3 horizontal lines often used to display the navigation menu link on mobile versions of websites
• HTML - HyperText Markup Language, the usual programming language used to create web pages. HTML consists of a series of opening and closing tags around content to be displayed e.g.

  This is my page title

  View source on any web page and you'll see the HTML that makes up that page.
• HTTP - an unencrypted method for transferring web pages and any information you enter into the web page across the internet
• HTTPS - an encrypted method for transferring web pages and any information you enter into the web page across the internet. See SSL
• Homepage - the page displayed to a user when they start their Web browser or click the 'home' button
• Host - the server on which a website resides, or the company that provides it
• Hosting company - a company that sells space on their web servers to the public
• Hyperlink - a link to another page, document, image or other media on a Web page
• IMAP - Internet Message Access Protocol, a way of setting up an email account in a mail programme which leaves emails on the server. This can end up taking up a lot of disk space. When you are given details to set up a new email account it may include the port number to be used for IMAP. See POP3
• Internet - the global, public computer network
• Internet Explorer - a series of web browsers developed by Microsoft. It has now been replaced by Edge, and only IE version 11 is supported. Many people across the world (particularly China) are still running old versions oF IE which have major security weaknesses.
• IP address - Internet Protocol address is a series of numbers that identifies you on the internet. If you're connecting to the internet at home or in an office, your public IP address is probably the numeric address of your router and it will be shared with everyone else on the same connection. Instructions for how to find out your IP address here.
• JPEG - a type of image file used mainly for photographs
• Java - a plugin made by Sun to allow more complex programmes to run on a web page
• JavaScript - a scripting language used for client-side functionality
• Landing page - the first page that visitors see, usually the home page but it could be the first page of a popular section e.g. online store. A landing page needs to tell visitors where they are, what the site is about, and quickly link them to other relevant sections. 
• Links in - getting links from other high quality, relevant websites to your website (links in) is one the key ways to improve search engine ranking, and perhaps the hardest to achieve. Shady SEO practices involve selling "links in" - don't trust these.
• Mailbox - the destination that emails are delivered to and from which emails can be sent.
• Malware - short for malicious software, it's an umbrella term for hostile or intrusive software including computer viruses, worms, Trojan horses, ransomware, spyware, adware, scareware, and other malicious programmes
• Meta tags - special tags (see HTML) in a web page to give particular information to search engines. There are a number of different types but most important are Title and Description; see SEO for more. 
• Mobile friendly - a website which looks good and is easy to use on a mobile phone. Google will test whether your web page is mobile friendly
• MySQL - an open source database system frequently used in conjunction with PHP and Apache to create dynamic Web pages
• Open source - a set of principles and practices on how to write software, the most important of which is that the source code is openly available
• Open data - large data sets of information made freely available, usually formatted to be machine-readable
• Opera - a freeware operating system for Windows, Mac or Linux. It has a relatively small market share apart from in several countries in Africa where it is the most popular browser (Statcounter August 2017).
• Organic traffic - visits to your website which result from being listed in search engine results rather than paid adverts
• POP3 - Post Office Protocol version 3, a way of setting up an email account in a mail programme which downloads emails to a computer or device. When you are given details to set up a new email account it may include the port number to be used for POP3. See IMAP 
• PHP - a computer language frequently used in conjunction with MySQL and Apache to create dynamic Web pages
• Plugin - an add-in programme for a web browser such as Flash or Quicktime
• PNG - an image file type suitable for graphics on the web, replacing the older GIF file type. PNGs can have transparent areas.
• Ranking - the order that a website appears in search engines results
• Responsive Design - creating web pages that adapt to different devices and screen sizes.
• Safari - a propriety web browser developed by Apple, which is the default browser on Apple devices and as a result the second largest market share. The PC version has been discontinued.
• Search engine - a website designed to search for information on the Web
• SEF - Search Engine Friendly, any system designed to improve the visibility of a site to a search engine
• SEO - Search Engine Optimisation, methods for improving a website's result position in a search engine
• Server - a computer that holds a web site and sends pages, images and other parts of a web page
• Server-side - refers to functionality and scripts that are performed on the Web server; see Client-side
• Site structure - a representation of the layout of a website, for example, a tree diagram with the home page at the top and all other pages branching off. See Anatomy of a Web Page.
• Social media - websites and apps which let you link up with others and join communities to share comments, photos and videos such as Facebook, Twitter, YouTube and Instagram. Also used by business and organisations for marketing. 
• SQL Server - a database system created by Microsoft
• SMTP - Simple Mail Transfer Protocol, the standard by which out-going emails are sent. When you are given details to set up a new email account it may include the port number to be used for SMTP. 
• SSL - Secure Sockets Layer (also Transport Sockets Layer) are methods to encrypt web browsing, emails, VoIP amongst others. To use it on a website you must obtain and install an SSL certificate. This is currently optional, but Google is increasingly penalising sites which do not have SSL certificates.
• Static - a Web page that doesn't include any rich functionality or database calls
• URL - Uniform Resource Location, otherwise known as a web address e.g. iteracy.com/blog/post/web-design-glossary
• Usability - quite simply, how easy a website is to use. It can cover everything from button size to layout of navigation.
• W3C -World Wide Web Consortium, the organisation that sets standards for the Web
• WAI - Web Accessibility Initiative, a set of standards created by the W3C to improve accessibility of websites. See our guide to WAI.
• Web page - a file usually written in HTML or XHTML programming languages that can be a read by a Web browser
• Website - a collection of Web pages, images or videos hosted on one or several Web server(s)
• World Wide Web - a system of linked documents accessed via the Internet
• XHTML - Extensible HyperText Markup Language, the latest version of HTML; see HTML
• XML - Extensible Markup Language, a general-purpose markup language upon which XHTML is based. Often used for Open Data datasets.