Booleans are used in Gmail filters just as in search. You can add search terms such as AND or OR or NOT in all search fields. If you want to create a filter to delete all spam mails sent from different email address, you may include email addresses separated by OR in "From" text box. For example it may look like this: (spammer1@abc.com) OR (spammer2@xyz.com) OR (spammer3@pqr.com). The Boolean search term OR successfully replaces the need to create separate filter for spam mail sent from different email addresses.
Search operators such as hyphen (-), quotes (""), parenthesis ( ) and search terms like "has:", "is:", "filename:", "label:" and other terms would also be used to groove up the Gmail search. Get complete list of search operators here at Using advanced search.
Google labels are of great help to separate email and organize your inbox. Gmail labels and filters go hand in hand. You can set action to put the mails arriving to your email address directly to these labels.
You can use the Gmail filters and labels to send spam directly to trash; separate emails which has attachments, media and blog comments; delete old mails; create back up of your inbox and so on. There are limitless possibilities.