If you need to just find a contact and you know the name or company, you can simply use the Search Everything box. However, if you need to find a list of contacts that have a specific set of data, you will need to use the filters.
There are simple and advanced filters. With the simple filters, you type in the data you want (or select from a drop-down menu, pick a date, check a box, or click on a tag). Once you click outside the field, your list will be narrowed down.
However, there are times that you need a more advanced search. For instance, you need to find all of the contacts that were created this month or all contacts that do not include a specific status. For these cases, you will need to use the Advanced filters.
To use the Advanced filters, switch to the advanced filters. Click "Add a Filter", find the field you need to filter by, and then select the options (the options are based on the type of field you have selected.)