File:  On a PC, a file is  a block of information. It's like a physical sheet of paper in that it has size, location, etc. A PC file can also be of different types, like files that contain words, files that do things (programs), or even files that contain other files (like zips or archives).

RAM or Memory: RAM (Random Access Memory) is what a computer uses to do things. Everything has to be in RAM to do anything. Programs are loaded into RAM to run. All the computer's processor really does is manipulate RAM. In human terms, when you read a page, you're putting that information into your RAM.

Storage or Hard Drive Space or Disk Space: A hard drive is a place where things are stored for the long term. Think of the Hard Drive as a "File cabinet". When you want a file, you go to the file cabinet, open it, and read the document. On a PC, when you want a document your program (like a word processor) will load the file from the harddrive into RAM so you can see it. The harddrive is long term, and RAM is short term and where your PC "thinks".

Directory or Folder:  This is an organizational tool on a PC. A directory or folder is a place on a drive where you can put files.

Program: a program is a file on the PC with a special structure that allows it to do things like draw screens, show information, etc.  Common programs include Microsoft Word or Excel, Internet Explorer and, of course, IPM.

Database: a database is a file on the PC that contains all the information about your checkbooks, properties, units, tenants and transactions. The most common correllary is an Excel spreadsheet, where each row would be a tenant, for example. IPM "views" your database and allows you to work with it.