The first advances in computing really took place in the 1940's but even before that, people were working on machines that would lay the groundwork for today's computers.
In 1939 Professor John Atanasoff and his student Cliff Berry started work on the Atanasoff-Berry Computer (ABC). Atanasoff tried to patent the computer, but only succeeded in patenting some of his ideas. The computer itself was declared un-patentable and this landmark sentence resolved in the computer becoming freely open to anyone. The ABC itself was completed in 1942.
1941 saw the unveiling of the Z3 computer by Konrad Zuse. It was a fully operational calculating machine. In 1944, Colossus, the first binary and partially programmable computer was operational at Bletchley Park, England. It was created by engineer Tommy Flowers and was used to break the complex Lorenz codes used by the Nazi's during the Second World War, cutting the code cracking time from weeks to hours.
The latter end of the forties saw Claude Shannon of the Massachusetts Institute of Technology build the first machine that plays chess and the founding of the first computer company, Electronic Controls Company, by John Mauchly and J. Presper Eckert.
The fifties brought yet more advances. In 1950, Hideo Yamachito created the first electronic computer and in 1951 the first business computer, the Lyons Electronic Office (LEO) was completed, to solve clerical problems. The first commercial computer, the "First Ferranti MARK I" at Manchester University also started work.
In 1953, IBM released their first computer – the 701, of which 19 units were made and sold. In 1954 they released the IBM 650 that sold much better.
In 1955, Tim Berners-Lee was born. He would go on to invent the internet at CERN, which itself was established in 1954. The internet revolutionized the world of computers.
The 40's, 50's and 60's are where the computer evolved and started to develop potential for the many applications it has today.