Filters allow you to view a selection of log items according to a given search condition.
For simple queries, you can use the quick filter. With the quick filter you can select log entries based on the value of one column. For example, you can display all the log entries with a Severity higher than Warning.
If you need to search log entries based on the value of more than one column, you can setup a custom filter. For example, this would be the case if you need to find all the log entries of a certain severity which occurred after a certain date. You can use a custom filter once or you can save it with a name, for later reuse.