Capitalisation?

[BuckBuck]

Does capital letters afferct ranking? This is strange and does not make pretty much sense but make a quick experiment. Go to google and search for a particular word like i did with ranking. Once i search for "Ranking" with capital R and once "ranking" with no capital letter. The result:

Ranking - 10 900 000
ranking - 10 600 000

So how do capital letters affect ranking? And how do we use it in our favour?