All Glossary Items

Alternative text, or ‘alt text’, ‘alt tags' and/or ‘alt descriptions', is the written copy that appears in place of an image on a webpage if the image fails to load on a user's screen, it is the written copy displayed in place of those images.

A file with the SVG file extension is most likely a Scalable Vector Graphics file. Files in this format use an XML-based text format to describe how the image should appear (XML, or Extensible Markup Language, is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable).

A react image is an img tag replacement and hook for React.js; we could say it is a declarative, efficient, and flexible JavaScript library for building user interfaces. React Image allows one or more images to be used as fallback images, in case the browser couldn't load the previous image.

Basically, a raster graphic is a bitmap, which in turn is a grid of individual pixels that compose an image as a whole. This kind of graphics render images as a number of countless tiny squares, also called pixels. And each pixel is coded in a specific shade.

Largest Contentful Paint, or LCP, is a performance metric that measures how long it takes for the main content of a website to download and become visible within your visitor’s viewport. In a few words, it is the biggest visual part of the page.

AVIF stands for AV1 Image File Format and it’s the next-generation image format, because of its quality and size. An AVIF image normally it’s 50% smaller than JPG.

Lazy Loading is a technique that loads the images of a website only when they are needed. Like it´s shown in the video below. The images will be loaded only when the user scrolls (when the user needs the content.)

CDN stands for Content Delivery Network and are deployed in data centers. It is a large network designed to deliver all the content of your website accessing from the closest location.

JPEG or JPG stands for Joint Photographic Experts Group. It is lossy format and super lightweight. JPG is a very used image format, with compressed image data.

PNG stands for Portable Network Graphics, and it is an image format used for websites and not for printing. One of the advantages of PNG is that it allows saving the image with a transparent background. It is super common using PNG format in logos, icons, for example.