Blob
Binary Large Object - an immutable object representing raw binary data in the browser, widely used for reading and writing image files in JavaScript.
A Blob (Binary Large Object) is an immutable object representing raw binary data in the browser's JavaScript environment. In image processing, Blobs hold image data from file inputs or Canvas output, enabling download and upload operations.
The File object inherits from Blob, so images selected via <input type="file"> are directly usable as Blobs. The Canvas API's toBlob() method converts rendered content into a Blob in JPEG, PNG, or WebP format.
URL.createObjectURL(blob) generates a temporary URL for use in <img> elements or download links. The image compression tool uses blob.size to display file size comparisons. To prevent memory leaks, unused Object URLs must be released via URL.revokeObjectURL().