Understand the terms behind web pages, links, email, databases, and everyday technology. Each guide starts with a plain-language explanation and develops it through examples you can follow.
For a first tour of the web, start with URL, continue to HTTP, then explore HTML. MIME explains how those exchanges identify their content. Use the topic groups below for a specific question.
Understand the web
How to Read a URL: Domains, Paths, Queries, and Fragments
A URL identifies a resource and how to access it.
Learn to identify the parts of a web address, resolve relative links, and check where a link leads.
HTTP and HTTPS: Requests, Responses, and Status Codes
HTTP defines requests and responses between clients and servers.
Follow a browser request, interpret headers and status codes, and understand what HTTPS protects.
What HTML Does: A Small Web Page Explained
HTML gives web content structure and meaning.
Read and edit a small semantic HTML document, with a downloadable practice page and clear examples.
MIME Types: How Email and the Web Identify Content
MIME describes content formats and multipart messages.
Understand Content-Type, multipart email, attachments, and the difference between a filename and a media type.
Work with data and code
SQL Explained with Queries You Can Follow
SQL expresses operations on relational data.
Learn SELECT, filtering, joins, and grouped counts using a small fictional dataset and tested SQLite exercises.
Perl Explained: Text Processing and Existing Scripts
Perl is a programming language with strong text-processing facilities.
Follow a small Perl program, verify its output, and learn how to approach an existing script and its dependencies.
Decode technology language
Technology Terms That Help You Read Product Specifications
Technical specifications describe capacity, speed, delay, and compatibility.
Separate capacity, speed, delay, and compatibility so technical specifications answer your actual question.
Understand document history
SGML, XML, and HTML: Understanding Structured Documents
SGML provides a framework for defining structured markup languages.
Understand SGML’s historical role, distinguish document rules from presentation, and choose the right parser for a format.
Related reference libraries
- Browse the A–Z glossary for additional terms and acronyms.
- Explore networking guides for connections, infrastructure, and operations.