What are patches

If you are developing software, you know that there is nothing constant in a software product; only modifications are constant. As soon as one program is provided to a consumer, you immediately receive a list of desired changes for the following version. And this list counts hundreds of items.
How do you like the idea of distributing a short file instead of the whole program, when a small modification was made?

Why do you have to replace the whole database if you need to update just a few records? That's enough to send a small file containing changes. There can be no end of similar situations.
For example, if you were doing remote sales, you could upload the modifications directly to your customers or to the storehouse databases much more frequently and by the shortest possible time.

And what about the updates of the documents? Every time you have updated the document all you need is to email a file with those updates instead of redistributing the whole document.

After the installation of the changes consumer gets a full new version of the product or document as if he obtained the whole version.

Advantages of patches using:

	small size of patch files (products of many megabytes size can be updated with files of few kilobytes)
	possibility to distribute updates via email or internet
	increasing speed of updating
	protection against illegal use of your products and a possibility of distributing free updates since correct updating requires already installed old version that only legal users have.