FIRST, THE DESIGN
Just like civil engineers building a bridge, software engineers building a grid must specify an overall design before they start work. This design is called the grid architecture and identifies the fundamental components of a grid's purpose and function.

NEXT, THE HARDWARE
A grid depends on underlying hardware: without computers and networks, you can't have a grid!

THE CRUCIAL COMPONENT? MIDDLEWARE
Middleware makes grid computing possible. Middleware organizes and coordinates separate grid resources to create a coherent whole. Middleware is conceptually "in the middle" of operating systems software (like Windows or Linux) and applications software (like a weather forecasting programme).