What Allan said .
I use both routinely, but on an unscheduled "whenever I feel it needs to be done" basis. I consider each a part of basic system maintenance, much more important than updating drivers and all the other small fish that some users obsess over.
In general...if the 3-step chkdsk runs on its own prior to boot...that should be followed by running chkdsk /r on whatever partition prompted the 3-step chkdsk at boot (it's not always the system partition that needs chkdsk /r). Every partition (other than those on an SSD) needs chkdsk /r, followed by an occasional defrag, IMO.
A user can take a look at the errors reflected in Event Viewer and make a guess as to what might be wrong. Windows will usually start compiling various errors when system files are damaged or missing...a good start to troubleshooting errors with no obvious clues...would be to run chkdsk /r and follow with sfc /scannow, eliminating obvious possible causes before moving on to other guesses.