What is the difference between image ALT tag and image Title tag?

Alternate text(ALT text) is an attribute added to an image tag in HTML and Image title is another attribute that can be added to the image tag in HTML. It is important to include both image alt text and image title text in the image for important images on the page.

ALT text or ALT attribute (sometimes incorrectly used as "ALT tag") is the important text of the image, that is understandable by Google and other search engines. ... Title text or Title attribute (often incorrectly used as "Title tag") is the text of images which a user sees after hovering over the image.

ALT = an attribute added to an image tag in HTML. This will displayed in the image container when the image cannot be displayed.
Title =  This attribute is provide additional information about the image.