Looking at how much space you have left on your computer hard drive.
Sometimes, your computer runs slow because you start to run out of space on your hard drive. If this happens, you may get a “Low Disk Space” error.
Knowing how long it takes to download files. Larger files will take longer to download.
Knowing how much space you have in your e-mail inbox.
Shopping for SD memory cards, USB flash drives, or external hard drives.
For example, a 2 GB SD card will hold about 770 photos on a 10 megapixel camera.