✦ Understand & Apply ✦

Glossary of Terms

Practical explanations of the terms you actually need to know — no fluff, just clarity.

Image & PDF Terms

5 terms

What is DPI and why does it matter for my images?

DPI stands for Dots Per Inch — it's how printers and screens measure image resolution. For web images, 72 DPI is standard and keeps file sizes small. For printing, 300 DPI ensures sharp, professional results. If your images look pixelated when printed, the DPI is too low. If your web images load slowly, the DPI is too high.

WebP vs JPEG vs PNG: Which format should you use?

JPEG is best for photographs — it compresses well but loses some detail. PNG supports transparency and is perfect for logos and graphics. WebP is Google's modern format that compresses better than both, giving you smaller files for faster websites. If you care about page speed, WebP is the way forward. For print, stick with JPEG or PNG.

What is PDF/A and why do I need it?

PDF/A is a special version of PDF designed for long-term archiving. It embeds all fonts and forbids features that might break in the future, like external links or JavaScript. If you're sending legal documents, financial records, or anything that needs to be readable 50 years from now, PDF/A is the standard.

What is a watermark and how do I add one?

A watermark is a visible logo, text, or pattern placed on an image or document to protect it from unauthorized use. It helps you establish ownership and build brand recognition. For images, a watermark discourages theft. For documents, a watermark can mark something as "Draft" or "Confidential."

What resolution do I need for passport photos?

The standard passport photo requirement is 600x600 pixels at 300 DPI, which translates to a 2x2 inch physical size. Many online forms and government systems reject images that don't meet these specifications. To avoid rejection, crop your photo to the correct dimensions, ensure the background is plain white, and keep the file size under 240KB.

Office & Operations Terms

4 terms

What is a QR Code and how do I use one?

A QR Code is a square barcode that stores information like URLs, text, or contact details. Scanned with a smartphone camera, it instantly directs users to your content. QR codes are everywhere — from restaurant menus to event registration, product packaging to business cards.

What is a SKU and why do I need one?

A SKU (Stock Keeping Unit) is a unique code that identifies a specific product in your inventory. It helps you track stock, manage orders, and reduce errors. Unlike a barcode which is universal, a SKU is your own system — you decide how to structure it.

What's the difference between a barcode and a QR code?

Barcodes are linear (one-dimensional) and store limited information — usually just a product number. They're used in retail and inventory management. QR codes are two-dimensional and can store much more data — URLs, text, contact details, and more.

What is an invoice and what should it include?

An invoice is a formal document that records a transaction between a buyer and a seller. It includes important details like products or services provided, quantities, prices, payment terms, and due dates. Invoices are essential for accounting, tax compliance, and professional relationships.

Website & SEO Terms

6 terms

What is SEO and why does it matter for your website?

SEO (Search Engine Optimization) is the practice of making your website visible in search engines like Google. When someone searches for a term related to your business, you want your site to appear. SEO improves your rankings organically — without paying for ads.

What is a sitemap and do I need one?

A sitemap is an XML file that lists all the pages on your website. It acts as a roadmap for search engines, helping them find and index your content faster. If you have a large site, new pages, or frequent updates, a sitemap is essential.

What is a canonical tag and why does it matter?

A canonical tag tells search engines which version of a page is the "master" copy. If you have multiple pages with the same content, you risk duplicate content penalties. For example, if your product page is accessible via multiple URLs, a canonical tag consolidates the ranking signals.

What are Open Graph tags and how do they improve social sharing?

Open Graph tags are small pieces of code that control how your content appears when shared on social media platforms like Facebook, LinkedIn, and X (Twitter). They define the title, description, and image displayed in social posts.

What is Hreflang and when should I use it?

Hreflang is an HTML attribute that tells search engines which language and region a page is targeting. If you have a multilingual website, hreflang ensures Spanish-speaking users see your Spanish page, not your English page.

What is JSON-LD and why does it matter for SEO?

JSON-LD is a format for structured data that helps search engines understand your content. It powers rich snippets — those enhanced search results with star ratings, event dates, and product prices. If you want your content to stand out in search results, JSON-LD is the way to go.

Developer Terms

4 terms

What is JSON and why is it everywhere in web development?

JSON (JavaScript Object Notation) is a lightweight data format that's easy for humans to read and machines to parse. It's the backbone of modern web APIs, allowing websites to exchange data with servers seamlessly. When an app fetches data from a server, it's usually in JSON format.

What is an API and how does it work?

An API (Application Programming Interface) allows different software applications to communicate with each other. Think of it as a messenger that takes your request, tells a system what you want, and returns the response. When you log in with Google, check the weather on your phone, or process a payment online — you're using an API.

What is Base64 encoding and when is it useful?

Base64 is a method of converting binary data (like images or PDFs) into plain text. It's used when you need to embed files into HTML, CSS, or JSON — for example, embedding a small image directly into a webpage to reduce HTTP requests.

What is JWT and why is it used for authentication?

JWT (JSON Web Token) is a secure way to transmit information between parties as a JSON object. It's commonly used for authentication — when you log into a website, you get a JWT that proves you're authorized to access protected pages. JWTs are compact, secure, and work across different domains.

✦ Explore More ✦

Popular Glossary Terms

Most searched terms in our glossary.

Glossary

What are Open Graph tags and how do they improve social sharing?

Open Graph tags are small pieces of code that control how your content appears when shared on social media platforms lik...

Read more
Glossary

What is a sitemap and do I need one?

A sitemap is an XML file that lists all the pages on your website. It acts as a roadmap for search engines, helping them...

Read more
Glossary

What is an invoice and what should it include?

An invoice is a formal document that records a transaction between a buyer and a seller. It includes important details l...

Read more
Glossary

What is a watermark and how do I add one?

A watermark is a visible logo, text, or pattern placed on an image or document to protect it from unauthorized use. It h...

Read more
Glossary

What is Base64 encoding and when is it useful?

Base64 is a method of converting binary data (like images or PDFs) into plain text. It's used when you need to embed fil...

Read more
Glossary

What is DPI and why does it matter for my images?

DPI stands for Dots Per Inch — it's how printers and screens measure image resolution. For web images, 72 DPI is stand...

Read more
Glossary

What is PDF/A and why do I need it?

PDF/A is a special version of PDF designed for long-term archiving. It embeds all fonts and forbids features that might ...

Read more
Glossary

What resolution do I need for passport photos?

The standard passport photo requirement is 600x600 pixels at 300 DPI, which translates to a 2x2 inch physical size. Many...

Read more

✦ Got Questions? ✦

Frequently Asked Questions

Everything you need to know about our glossary and definitions.

What is a glossary and why is it important?

A glossary is a collection of terms and their definitions. It helps users understand technical language, learn new concepts, and navigate the world of online tools with confidence. A well-organized glossary also improves SEO by answering the questions people are actually searching for.

How do I find a specific term in the glossary?

Are the definitions in this glossary accurate and up-to-date?

Can I suggest a term to be added to the glossary?

Are these terms related to the tools on Destolo Labs?

How can a glossary help my website's SEO?

What is a long-tail keyword and why does it matter?

How often is the glossary updated?