What is a Google fight?

When you search to compare the number of results for two competing keywords. For example I wanted to know whether EFL or ESL was the most used term to describe teaching English as a second (or foreign or other) language. For those of you who won't sleep without knowing who won this epic Google-fight, ESL was the clear winner.

Many thanks to Chiew @ClilToClimb for bringing this to my attention.