I come across this word alot and I get confused of it's meaning as the definition change from one context to another. so what is the real meaning of checksum in a simple English.

I am programmer and I have seen it in many topics/books and the meaning changes slightly, sometimes it is used to mean result other times it is used as a verification or confirmation , also English is not my mother tongue, hence the confusion

  • What does the dictionary say? Oct 22, 2018 at 6:47
  • a digit representing the sum of the digits in an instance of digital data. but doesnt this means result?
    – ma1169
    Oct 22, 2018 at 6:52
  • Yes, a checksum is the result of performing a checksum function or checksum algorithm. Oct 22, 2018 at 6:56
  • I can only tell you how accountants use it. A checksum is used to verify that the answer in some other calculation is correct. It stands apart from the calculation itself, and typically uses data from another source, or uses a different formula, to independently prove that the answer in the calculation is correct. If the checksum and the answer in the calculation are different, it proves that the latter contains an error. Accountants use it a lot.
    – BillJ
    Oct 22, 2018 at 7:01
  • Hello and welcome. You will need to supply example sentences. Otherwise it is completely unclear what "slight changes in meaning" you have in mind. Though frankly, the meaning should be clear and self-explanatory from the context, especially if you are a programmer as you say. On a side note, there is no such thing as "alot", and do look up the difference between "its" and "it is". These are two completely different things.
    – RegDwigнt
    Oct 22, 2018 at 9:07

1 Answer 1


Checksums are used in a variety of ways because they have a variety of uses. As with any programming situation, we need to read the documentation.

That said, a checksum is a number that is often used to confirm that an operation is successful. For example, when we download a file it might include a checksum value. This value might be the size of the file in bytes: if the downloaded file size matches the checksum, it is presumed that the download has been successful.

Really this is a programming question.

  • 1
    Uhm, no; a checksum is not the size of the file. Oct 22, 2018 at 7:29
  • it's not just programming question, it exists in other fields too but because i am not native it's confusing. I took it in cryptography in md5 checksum algorithm for verification. and in assembly and some coding examples, they named normal result variables as checksum in their examples, which has nothing to do with the verification methods which is confusing. and in the dictionary the definition looks like result, and those who name it both are native english, and some people will say it means either just result or verify. and all i care about is what is the meaning and how to use it
    – ma1169
    Oct 22, 2018 at 7:45
  • @ma1169 In such examples they may refer to the results as checksums, because they are also using the results to check that they results are valid. That is all a checksum is: a number that we can use to check the validity of a process. How to use it is a different question, because it is not a programming, cryptographic or whatever method, it is the name of a variable. When you see 'checksum' mentioned, you have to read the documentation to determine what is being verified. Oct 22, 2018 at 9:33
  • ah thanks this explains it, and also i meant how to use it in context because some words have different meanings and the way it is used gives a different meaning
    – ma1169
    Oct 22, 2018 at 22:54

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