Stands for "Personal Information Manager."
A Personal Information Manager is a category of software application that helps manage all sorts of personal information, from notes and office documents, to contacts, photos, or a personal journal. A PIM app can focus on a single kind of information, like a calendar or note-taking app, or it can be a comprehensive suite of tools that manages multiple types of information. Since many operating systems now include a few simple built-in PIM tools like calendars and email clients, many third party PIM apps focus on taking those features and making them more comprehensive and customizable.
PIM software stores the information entered into it in a database. Notes, saved documents, appointments, and anything else in that database is easily accessed. Some PIM software stores that database in the cloud to make it accessible from multiple devices or a web browser. Since this personal information can be very private, some PIM databases can be encrypted to keep the data secure.
PIM software was a major feature of Personal Digital Assistants like the Palm Pilot and the Apple Newton. Now that smartphones have replaced PDAs, mobile operating systems include many PIM features. In addition to a smartphone's built-in calendar, contacts, and note-taking apps, some popular PIM software titles include Evernote, Microsoft OneNote, and DEVONthink.