Within Locable you can add both Alt Tags and Title Tags to your images. These are useful for search engines, internet users who use screen readers and certain unusual circumstances.
What is an Alt Tag
An Alt Tag is a description of the image. Users will see this displayed if the image URL is wrong, the image is not in one of the supported formats, or if the image is not yet downloaded.
You can read a complete description at https://en.wikipedia.org/wiki/Alt_attribute
What is a Title Tag?
A Title tag is a title for the image. The text will be used as the caption (when present) and displayed in a tooltip when hovering over the element.
How do I set the Tags?
You can set both Alt and Title tags in a few different places. When you're working with content or pages and you upload an image you can define the tags. Alternatively, you can browse all of your images by visiting Manage Content > Media Manager then select images to add/edit tags.
Should I take the time to add these tags?
It depends. Ideally, when you upload images you add these tags one at a time so it only takes a few seconds. These tags do help with SEO (search engine optimization) but not nearly as much as consistently creating and distributing good content that people want to read and share or collecting customer reviews.
So, you decide but focus on the activities have have the highest value for your time.