If so you are in a large majority, you would be extremely hard pushed to find someone who hasn’t been affected by delays or canceled flights at one time or another. Of course not all flight cancellations or delays can be avoided as some are out of human hands.

Some delays or cancellations can be down to sheer bad luck when it comes to Mother Nature. Bad weather is a huge problem where flights are concerned and for safety reasons flights are either delayed until it clears or cancelled for another time. Traffic control errors or problems can also be a factor when flights are either cancelled or delayed. Mechanical repairs or problems could also be another cause.
The majority of good airlines will do everything they can to find you another flight either with another airline or with them at a later date. There should be no other charges for this if the delay or the cancellation is out of your hands. If you find your own flight on a different airline your old airline may pay any fees but they are not at liberty to do so.