To clear the confusion, I-League remains India's premier football tournament and it is what is recognised as the most important one by the world governing body - FIFA.
As FIFA Secretary General Jerome Valcke said, "For us (FIFA), I-League and not ISL is India's biggest football competition. ISL is a championship of eight franchises for two months. You cannot have two leagues in a country. Football doesn't work like that. I-League is most important for development of football in India."
'ISL is booster dose'
AIFF President Praful Patel too said how important I-League is. "Let us not confuse the issue. ISL is a tournament that brings attention to football. It is like a booster dose," he said.
"ISL is created with the aim of strengthening the I-League. For football to develop here, infrastructure and youth development is the most important aspect we need to focus on," he added.
It was in 2010 that AIFF signed a 15-year agreement worth Rs 700 crores deal with International Management Group (IMG) and Reliance Industries Limited to start ISL.
Each country has its own football league and there is only one professional league in every country.
AIFF, however, has given the green signal for a second league with the franchise model, on the lines of cricket's Indian Premier League (IPL).
I-League is the "Indian National League". It is contested by different clubs in India. Last season sawa Bengaluru FC take the trophy. There were 13 clubs in 2013-14 season.
I-League begins in December
The 2014-15 season will get under way in December this year after the completion of ISL, which ends on December 20. I-League goes on for about 5 months.
For this season, there will be 11 teams. From the last edition, AIFF barred three clubs - Chruchill Brothers, United Sports Club and Rangdajied United FC for failing to meet the club licensing criteria.
Just like cricket where we have BCCI conducted national tournaments, AIFF too has I-League has main event and ISL now on franchise model.
Though in cricket we have different formats - four-day, one-day (50 overs) and Twenty20 (T20), in football there is only.
Even BCCI has its own national T20 competition, Syed Mushtaq Ali Trophy contested by state teams and IPL, which is a franchise-owned, cash-rich event for clubs.
As in the case of IPL and other national tournaments where the prize money difference is huge, the same is reflected in I-League and ISL.
I-League winners receive a trophy and Rs 70 lakhs while ISL champions get a whopping Rs 8 crores.
Amidst all the hype surrounding ISL, it remains to be seen whether it helps Indian football and has a destructive effect. IPL is already being blamed for destroying India's Test team and the controversies of spot-fixing have hit the brand.
Few Facts on I-League (Guide on ISL is here)