Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass.
It is commonly an unwanted by-product of fires (including stoves, candles, oil lamps, and fireplaces), but may also be used for pest control (fumigation), communication (smoke signals), defensive and offensive capabilities in the military (smoke-screen), cooking, or smoking (tobacco, cannabis, etc.).

Many books have been written about Silicon Valley and the collection of geniuses, eccentrics, and mavericks who launched the "Digital Revolution"; Robert X. Cringely's Accidental Empires and Michael A. Hiltzik's Dealers of Lightning are just two excellent accounts of the unprecedented explosion of tech entrepreneurs and their game-changing success.

But Walter Isaacson goes them one better: The Innovators, his follow-up to the massive (in both sales and size) Steve Jobs, is probably the widest-ranging and most comprehensive narrative of them all. Don't let the scope or page-count deter you: while Isaacson builds the story from the 19th century—innovator by innovator, just as the players themselves stood atop the achievements of their predecessors—his discipline and era-based structure allows readers to dip in and out of digital history, from Charles Babbage's Difference Engine to Alan Turing.