Filtering which cells are visible
A filter is a list of conditions that each entry has to meet in order to be displayed. You can set three types of filters from the Data > Filter sub-menu.
Automatic filters add a drop-down list to the top row of a column that contains commonly used filters. They are quick and convenient, and, because the condition includes every unique entry in the selected cells, are almost as useful with text as with numbers.
In addition to each unique entry, automatic filters include the option to display all entries, the ten highest numerical values, and all cells that are empty or not-empty, as well as a standard filter. Their drawback is that they are somewhat limited. In particular, they do not allow regular expressions, so you cannot display contents that are similar, but not identical, by using automatic filters.
Standard filters are more complex than automatic filters. You can set as many as three conditions as a filter, combining them with the operators AND and OR. Standard filters are mostly useful for numbers, although a few of the conditional operators, such as = and < > can also be useful for text.
Other conditional operators for standard filters include options to display the largest or smallest values, or a percentage of them. Useful in themselves, standard filters take on added value when used to further refine automatic filters.
Advanced filters are structured similarly to standard filters. The differences are that advanced filters are not limited to three conditions, and their criteria are not entered in a dialog. Instead, advanced filters are entered in a blank area of a sheet, then referenced by the advanced filter tool to apply them.