Occasionally, I have come across Drupal sites that have base64 encoded images embedded into content fields. This is the approach of taking the binary data contained in a file and converting it into a string of characters. The original binary data can then be re-created using this string and the data is understood by lots of different technologies (including web browsers).
Whilst this is technically possible, it massively balloons the size of the database and can often slow down page load times due to the database being slow to respond to the request. Instead of fetching a few kilobytes of data from the table the database is forced to fetch many megabytes of data, which can create a bottleneck for other requests.
When you download a file from the web your browser can make a decision on whether to fetch that file a second time. By injecting files into the content you are forcing your users to download very large pages every time they want to request a page. It isn't possible for the browser to make that decision any more and that can lead to more slowdown for the user.
If you can't tell, I really dislike this method of image storage. Whilst it is technically possible, it creates more problems than it solves and even sites with a couple of thousand nodes can have databases of many gigabytes in size due to this issue. It can also put unnecessary strain on the database due to the increased time taken to return data.
Read more here: https://www.hashbangcode.com/article/drupal-9-removing-base64-encoded-files-content