Three of the comparison methods for filter conditions are Contains, Matches, and Is. These options appear for some items such as the subject line.
Contains means that the specified line must contain, somewhere within it, the specified string. For example, specifying that the subject line contains "bananas" would match both "Cooking with bananas" and "Bananas for breakfast".
Matches means that the specified line must exactly match the specified string, which may include wildcards. For example, specifying "bana*" would match "banana" and "banana tree but not "free bananas".
Is means that the specified line must exactly match the specified string, with no wildcards or substitutions. For example, specifying that the subject line must match "bananas" would only match "bananas" and not "Banana", "My bananas", or "Bananas?"