A spider (also called a web crawler or bot) is an automated program that browses the internet to index web pages. These programs are often used by search engines like Google, Bing, or Yahoo to discover and update content in their search index.
Starting Point: The spider begins with a list of URLs to crawl.
Analysis: It fetches the HTML code of a webpage and analyzes its content, links, and metadata.
Following Links: It follows the links found on the page to discover new pages.
Storage: The collected data is sent to the search engine’s database for indexing.
Repetition: The process is repeated regularly to keep the index up to date.
Search engine optimization (SEO)
Price comparison websites
Web archiving (e.g., Wayback Machine)
Automated content analysis for AI models
Some websites use a robots.txt file to specify which areas can or cannot be crawled by a spider.
A crawler (also known as a web crawler, spider, or bot) is an automated program that browses the internet and analyzes web pages. It follows links from page to page and collects information.
Search Engines (e.g., Google's Googlebot) – Index web pages so they appear in search engine results.
Price Comparison Websites – Scan online stores for the latest prices and products.
SEO Tools – Analyze websites for technical errors or optimization potential.
Data Analysis & Monitoring – Track website content for market research or competitor analysis.
Archiving – Save web pages for future reference (e.g., Internet Archive).
Starts with a list of URLs.
Fetches web pages and stores content (text, metadata, links).
Follows links on the page and repeats the process.
Saves or processes the collected data depending on its purpose.
Many websites use a robots.txt file to control which content crawlers can visit or ignore.
An Internationalized Resource Identifier (IRI) is an extended version of a Uniform Resource Identifier (URI) that supports Unicode characters beyond the ASCII character set. This allows non-Latin scripts (e.g., Chinese, Arabic, Cyrillic) and special characters to be used in web addresses and other identifiers.
A-Z
, 0-9
, -
, .
, _
), IRIs allow characters from the entire Unicode character set.https://de.wikipedia.org/wiki/Überblick
https://de.wikipedia.org/wiki/%C3%9Cberblick
Ü
is encoded as %C3%9C
)IRIs are defined in RFC 3987 and are supported in modern web technologies like HTML5, XML, and RDF.
IRIs make the internet more linguistically inclusive by allowing websites and resources to be referenced using non-Latin characters, improving accessibility worldwide.
A SUT (System Under Test) is the system or component being tested in a testing process. The term is commonly used in software development and quality assurance.
A typical testing process includes:
SSH (Secure Shell) is a network protocol that establishes an encrypted connection between two computers. It is mainly used for securely logging into remote systems (e.g., servers) and executing commands.
ssh username@server-ip
scp file.txt username@server-ip:/destination-folder/
ssh-copy-id username@server-ip
SSH is commonly used by developers and system administrators to manage servers or establish secure connections for other applications.
TortoiseGit is a graphical user interface (GUI) for Git, specifically designed for Windows. It is an extension for Windows Explorer, allowing users to manage Git repositories directly via the context menu.
✅ Windows Explorer Integration → No separate tool needed; everything is accessible via the right-click menu
✅ User-Friendly → Ideal for those unfamiliar with the Git command line
✅ Visual Support → Changes, diffs, logs, and branches are displayed graphically
✅ Push, Pull, Commit & Merge → Perform standard Git operations via the interface
✅ Support for Multiple Repositories → Manage multiple projects simultaneously
TortoiseGit requires a Git installation (e.g., Git for Windows) to function.
➡ Download & More Info: https://tortoisegit.org/
A Single Page Application (SPA) is a web application that runs entirely within a single HTML page. Instead of reloading the entire page for each interaction, it dynamically updates the content using JavaScript, providing a smooth, app-like user experience.
✅ Faster interactions after the initial load
✅ Improved user experience (no full page reloads)
✅ Offline functionality possible via Service Workers
❌ Initial load time can be slow (large JavaScript bundle)
❌ SEO challenges (since content is often loaded dynamically)
❌ More complex implementation, especially for security and routing
Popular frameworks for SPAs include React, Angular, and Vue.js.
CSS Media Queries are a technique in CSS that allows a webpage layout to adapt to different screen sizes, resolutions, and device types. They are a core feature of Responsive Web Design.
@media (condition) {
/* CSS rules that apply only under this condition */
}
1. Adjusting for different screen widths:
/* For screens with a maximum width of 600px (e.g., smartphones) */
@media (max-width: 600px) {
body {
background-color: lightblue;
}
}
2. Detecting landscape vs. portrait orientation:
@media (orientation: landscape) {
body {
background-color: lightgreen;
}
}
3. Styling for print output:
@media print {
body {
font-size: 12pt;
color: black;
background: none;
}
}
✅ Mobile-first design: Optimizing websites for small screens first and then expanding for larger screens.
✅ Dark mode: Adjusting styles based on user preference (prefers-color-scheme
).
✅ Retina displays: Using high-resolution images or specific styles for high pixel density screens (min-resolution: 2dppx
).
Responsive Design is a web design approach that allows a website to automatically adjust to different screen sizes and devices. This ensures a seamless user experience across desktops, tablets, and smartphones without needing separate versions of the site.
Responsive Design is achieved using the following techniques:
1. Flexible Layouts
2. Media Queries (CSS)
@media (max-width: 768px) {
body {
background-color: lightgray;
}
}
→ This changes the background color for screens smaller than 768px.
3. Flexible Images and Media
img {
max-width: 100%;
height: auto;
}
4. Mobile-First Approach
✅ Better user experience across all devices
✅ SEO advantages, as Google prioritizes mobile-friendly sites
✅ No need for separate mobile and desktop versions, reducing maintenance
✅ Higher conversion rates, since users can navigate the site easily
Responsive Design is now the standard in modern web development, ensuring optimal display and usability on all devices.
A Bearer Token is a type of access token used for authentication and authorization in web applications and APIs. The term "Bearer" means "holder," which implies that anyone in possession of the token can access protected resources—without additional verification.
Authorization: Bearer <token>
.GET /protected-data HTTP/1.1
Host: api.example.com
Authorization: Bearer abcdef123456
💡 Tip: To enhance security, use short-lived tokens and transmit them only over HTTPS.