You may find yourself using a particular filter again and again. If it's a compound filter with lots of pieces, it's annoying to have to recreate the filter every time you need to use it.
Luckily, it's possible to save your filters and reuse them later.
In most places where you work with filters, you will see three buttons that look like this:
The first button is the "new filter" button. Clicking this button will wipe out the current contents of the filter editor and replace them with a brand new filter.
The second button is the "load filter" button. Clicking this button will bring up a window where you can choose a saved filter file from the disk. The filter will be read from the file and loaded into the filter editor.
The third button is the "save filter" button. Clicking this button will bring up a window where you can specify a file name for the saved filter file. The current filter will be saved onto the disk in the file you specify.