truncated file

can anyone explain to me what a truncated file is.
i have a canon powershot a700 camera. after i took pictures they came
on my playback as a corrupt file .
When i downloaded them to my computer they showed as beingeither a
truncated file or a corrupte file.
i would llike to know what i did wrong taking the pics.
Some of my othr pictures were fine taken at the same time.
Any advice would be appreciated. thank you.

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