When we create a document, there are many details that we can obtain from it. The metadata gives us a lot of information about the document that we have created, that data we can use or not, it depends on the use we want to give it. But within all that data, there is one called HASH. This data is an alphanumeric number that identifies the document that we have created, there cannot be more than one document with the same HASH code.
For example, if we create a document with a thousand pages right now, we save it with a specific format and name, it will be created with a HASH code. If in five minutes, I reopen the document and to those thousand pages, I add a simple comma, when I save it, that document will have a different HASH code, even if we have only added a comma. Any modification, the HASH code will change.
We have done this example with a document, but it also happens with photos, videos, audios… Anything that can be edited, its HASH code can also be altered.
On the Internet there are different applications to generate HASH codes, they also offer us the option of comparing these codes, to know, for example, if a photo that is ours and we publish it on the Internet, has been modified or not.
For your safety, you can see the HASH code of your data and save it in case in the future, you have to compare those files, if the codes match, it means that this file has not been modified, if they are different, that file has been modified.