Glossary

Networked computers

Server

A server is something which provides services to other computers or clients over a network (usually the internet). The term can mean the physical machine (hardware) or the program running on that machine (software). In web development, a server hosts websites, processes requests from clients (such as browsers), and serves web pages or data back to the clients. Example: Apache, Nginx, or Microsoft IIS are common web servers.

Client

A client is any device or software that requests services or resources from a server. In web development, a client is typically a web browser (like Chrome, Firefox, Edge, or Safari) that communicates with a server to retrieve web pages. Example: When you open a website in your browser, the browser acts as the client.

The World Wide Web

User

The end-user who interacts with a website or web application. Users input data, click buttons, and navigate through web pages. Example: You, as a user, are interacting with this web page right now!

Browser

A browser is a software application that allows users to access and view web pages. It interprets HTML, CSS, and JavaScript to display web content. Example: Chrome, Firefox, Safari, and Edge are popular web browsers.

Server-side

Refers to processes or code executed on the server. Server-side languages (like PHP, Python, or Node.js) handle data processing, database interactions, and business logic. Example: Processing form submissions, querying databases, and generating dynamic content.

Client-side

Refers to processes or code executed in the user’s browser. Client-side languages (such as JavaScript) enhance interactivity and manipulate the DOM (Document Object Model). Example: Validating form input, creating animations, and handling user interactions.

HTML (Hypertext Markup Language)

HTML is the standard markup language for creating web pages. It defines the structure and content of a web page using tags. Example: <h1> for headings, <p> for paragraphs, and <a> for links.

Tag

In HTML, tags are used to define elements within a web page. Tags are enclosed in angle brackets (< and >). Most tags have a matching closing tag, which is the same but with a / before the name. So the word chair here is emphasised because it is written <emph>chair</emph>. Some tags, like <input /> and <img />, are self closing, and don’t have a separate </> tag to end them.

Form

An HTML form is a container for input elements (such as text fields, checkboxes, radio buttons) that allow users to submit data to a server. Example: A login form with username and password fields.

CSS (Cascading Style Sheets)

CSS is used to style and format HTML elements. It controls the layout, colors, fonts, and other visual aspects of a web page. Example: Setting font size, background color, or margins using CSS.

Attribute

An attribute provides additional information about an HTML element. It is specified within the opening tag of an element. Example: The href attribute in an anchor (<a>) tag specifies the link destination: <a href="https://www.google.com/">.

Key-value pair

A key-value pair consists of a key (or property) and its associated value. It’s commonly used in data structures like dictionaries or objects. Example:

{
    "name": "John",
    "age": 30
}

(where “name” and “age” are keys, and “John” and 30 are values).

SQL

Structured Query Language (SQL) is a language used to manage and manipulate relational databases. It allows you to create, retrieve, update, and delete data. Example: Writing queries to retrieve specific information from a database.

Database

A database is a structured collection of data. It stores information in tables and allows efficient data retrieval and management. Many database systems are queried in SQL Example: MySQL, PostgreSQL, or SQLite databases.

Table

In a database, a table represents a set of related data organized into rows (called records) and columns (called fields). Example: A “users” table with columns (fields) for usernames, email addresses, and passwords. Each person who is added to the table will correspond to a new row (record) with values for each of the fields.

Field

A field (or column) in a database table represents a specific piece of data. Each row contains values for each field. Example: The “name” field in a “contacts” table.

Row

See record

Record

A record (or row) in a database table represents a single data entry. It contains values for all the fields. Example: A row in a “users” table would contain different pieces of information about a single user.

Value

Also known as a cell. This is a piece of information corresponding to a single field in a single record.

Query

A query is a request for specific data from a database. It can retrieve, filter, or modify data. Example: “SELECT * FROM users;”