Metadata is commonly defined as data about data. It could contain information about when, how and who collected and formatted the data. Because of its many uses, metadata can also be defined in many ways. But basically metadata refers to the description given to a resource.
Metadata is very much helpful in making searches possible and faster. Metadata dictates how items are related and how such relationships are to be evaluated in searches. In storing data into data repositories, metadata are also used. When it comes to documents, metadata usually describes the content of the data. It may also be about the time it was written and the source of the document.
Free metadata software are available for different types of resources. For instance, there is the Microsoft Photo Info 1.0. This software allows photographers to add and delete some metadata of a certain image.
The free metadata software available today ranges from free metadata viewer to free metadata tools. There are metadata tools that can be used for the creation of metadata for maps, data sets and models. There is even an application that would help create Federal Geographic Data Committee compliant metadata. There are metadata tools for library images too. They would usually enable reading, writing and deleting of metadata for specific images. There are also metadata tools that serve as browser editor and consistency checker.
So, just as there are so many metadata applications, there are also many metadata software. Each of which is geared to serve one or a general area. There are also some vendors and even agencies that offer them for free.