Question

Sometimes, when modifying a document with a word processor, adding text does not increase

the apparent size of the file in mass storage, but at other times the addition of a single symbol
can increase the apparent size of the file by several hundred bytes. Why?

Answer 1

The rotation speed of disks is measured in RPM.

Step-by-step explanation:

Storage space is allocated in units of physical sectors...

However, BMP images are not compressed, resulting in very large file sizes for any useful image resolutions. Example:

Beyond Compare is a utility for comparing files and folders. It can help you find and reconcile differences in source code, folders, images and data. File size is in mind though.

The reason behind to not increase the size of the file is in what you do with it.