I had my first experience with community when I moved to Missoula, MT.
Up until then, I had no clue what it meant meant.
I will substitute the word community with Missoula in the following:
Missoula has six gardens throughout town, and they are happily tended to by volunteers. There is so much food being grown that we feed many hundreds of homeless with organic vegetables.
Missoula is all about potlucks: friends coming together and sharing meals.
Missoula is called “The Garden City.” Most everyone has a garden and grows food. It’s said you should only eat food grown on your own soil.
Downtown stores are locally owned. Book stores, coffee shops, hubs where folks gather and exchange information. (Starbucks moved into a space downtown last year. Missoula did not support it and so, at the end of this month, they were forced to close their doors.) The majority of citizens care about keeping the ‘local flavor’ in tact. Why? Because we are family.
There is a bike trail system throughout, and a place called “free bikes” if you don’t have one. People who are just moving to Missoula learn very quickly that a bicycle is the preferred form of transportation. Less dependence on fuel. Less pollution. Less stress. Easy pace.
In Missoula people care about quality of life, about creating a place where children learn the 
importance of participation and contribution. To give is to receive is to give.
There is a collective consciousness that exists in Missoula, that harkens to a time when life was much more simple, where time is slowed down so that one can enjoy their environment, their people. To live in a conscious, meaningful way.
My definition of community: a quality of life that is self-sustainable and shared equally by conscientious participants. Missoula taught me what it means to live within a community. I am eternally grateful.