When you run out of space on your hard drive, one way to find out which files and folders are taking it up is to use a disk space analyzer.
A disk space analyzer (or disk space usage analysis software) is a utility that analyzes your disk space usage by checking each folder, sub-folder and each file on your drive for size.
There are a lot of applications designed to do this, both freeware and shareware. Most of them visualize the information they get from their analysis in the form of a graphical chart that shows disk space usage distribution according to a number of user defined criteria. Or they could list your files and folders in different user configurable ways.
One of well known disk space analyzers is ActiveSMART. In includes analyzing your free and used disk space and show the result in a nice graphical way, where all the disk space is at one glance.
Check the ActiveSMART screenshot below. Those rectangles are folders and files, and their size correspond to the size on the disk. You see the biggest files and folders.
Download ActiveSMART with disk space analysis
Result of disk space analysis in ActiveSMART
Usually you can make disc space analysers to include and exclude certain files and folders in their scan. Often they can export the results of the scan to other programs such as Excel and other file formats such as HTML.
Some of them can perform cleanups and scheduled file system scans. Some may use treemaps. Some can integrate with system shell.
The majority of disk space analysers also can calculate file checksums, find duplicated files and folders and even present disk health indicators using SMART technologies.