'Football' is entirely determined by the country you're in. As Peachey said, in Australia 'football' means rugby or AFL, depending on what state you're in. In the USA 'football' is American football. In Europe, 'football' is soccer. To reduce ambiguity, I suggest you never use the word 'football' online because everyone will interpret it differently.

It's difficult question to answer. Quote from wikipedia:"Football refers to a number of sports that involve, to varying degrees, kicking a ball with the foot to score a goal. The most popular of these sports worldwide is association football, more commonly known as just "football" or "soccer". Unqualified, the word football applies to whichever form of football is the most popular in the regional context in which the word appears, including association football, as well as American football, Australian rules football, Canadian football, Gaelic football, rugby league, rugby union,[1] and other related games. These variations of football are known as football codes." It's similar game but not the same way to play. some people call a game with round ball "soccer,football"; while some people called a game with oval ball "football,rugby,american football"

In the UK we say football, in the US they say soccer. I'm not sure about other English-speaking countries.

I think is depend of the country. Here in Latin America and I believe that in europe is the same, is called Football to the sport controled for the FIFA and I believe that in very few countries like US is called soccer because US people call football to another sport which is similar to rugby (American Football). Also the translation of soccer in spanish is Fútbol, that is pronounced in the same way that in english. Football, Fútbol or soccer is the most famous sport in the world and I'm refering to the sport that is played for players like Messi or Cristiano Ronaldo.

do you speak spanish?