Filters are files that allow you to import references saved from databases that do not have an automatic export feature. By selecting the correct filter, EndNote will transfer the information into the appropriate field in the EndNote record.
Import is the function, filters allow you to do it.
If the filter for your favorite database does not appear, download it from EndNote. They've got ~3000 to choose from.
Not all databases offer the direct export option. For those that don't you can use EndNote's import filters to transfer the reference data into your EndNote library. Here's how:
Here are some instructions for X3, old, but you should get the idea of what to do. Click here for more detailed instructions, Installing EncNote X3 Import Filter Download Instructions.