To apply filters on the Candidates grid, click on the rectangle under the name of the field you would like to sort and start typing the information you want to filter by. You can also click on the funnel symbol to apply filters more granularly.

Once you apply the filters, you can create lists, send blasts, export the filtered data, or save your filters for later use.
Click on the Actions button to view options for both adding the filtered contacts to a list, assign the contacts to a user, or create a filtered dynamic list:

Make Lists
Static vs Dynamic Lists
Once you've made your filters, you have the option to make both static lists as well as dynamic lists. A static lists is labeled as just 'list' and is a static group of contacts who can be added either through filters or imports. In a static lists, contacts can be added and removed without affecting the rest of the list.
A dynamic list on the other hand automatically adds and removes contacts who meet or don't meet a pre-defined filter criteria. Learn more about making and using dynamic lists here:
Create and Use Dynamic Lists