Filters allow you to include, exclude or change the way the data is shown in your reports. For example, you can create a filter to exclude IPs or to clean up URLs into readable text. If you have a filter that excludes an IP, any hit coming from that IP will be permanently removed from your report data.
In “Admin” page, select the view you want to add a filter to and click “Filter”. On the add filter page, you will be able to set the filter information like so: