Below are some real simple and non-technical definitions of computers.
Compact Disk (CD): is a permanent data storage device. It's usually used to bring information into the computer like installing programs or listening to music. Can also be used to store data from hard drive, for backup purposes.
Digital Video Disk / Digital Versatile Disk (DVD): similiar to CD but can hold more data such as movies.
Computer Case: this provide a protective covering for all of the electronic parts that are contained in it.
DIMM Slot: Dual Inline Memory Module is a type of Random Access Memory Module (RAM) that are small chips attached to a small printed curcuit board. The information that you see on your computer screen is temporarily stored here. When the computer is turned off, this information is wipe clean from the RAM.
Hard Drive/Hard Disk (HD): this is a device that permanently stores your data. Most HD are stored inside the case. The come in various sizes.
Floppy Drive: this is a low capacity permanent storage device that can be easily removed from the computer. Not the most durable media, and not in large us today.
Network Interface Card (NIC): a device that allows you to hook your computer to other computers via cables. This can also be hooked up to a DSL or Cable modem so you can access the internet.
Modem: a device that hooks up to your phone line so you can gain access to the internet. They can be installed internal (inside the case) or external.
Motherboard: this holds most of the electronic parts that are housed in the case.
Network: computers that are connected to each where they can communicate with each other. Internet access connects computers together. You can retrieve information or order products online from another computer that is located some where else. Thus, creating a network.
Parallel Port: a port on the back of the computer that is used to attach a printer. Other hardware devices can be hooked to it, but mostly only printers are attached to this port. This port is larger than the serial port.
PIC (Peripheral Component Interchange) Slot: a slot on the motherboard used to add components like a sound card, video card, NIC card, and modem.
PS/2: a port on the computer that keyboards and mouse connect to.
Serial Port: a port usually on the back of the computer that hooks up a external modem, mouse, joystick, printer and other gaming accessories to your computer.
Universal Serial Bus (USB): a port used to connect cameras, phones, ipods, PDA's, mouse, printer, scanners and many other devices.