It is a social group of any size whose members reside in a specific locality, share government, and often have a common cultural and historical heritage. A social, religious, occupational, or other group sharing common characteristics or interests and perceived or perceiving itself as distinct in some respect from the larger society within which it exists such as the business community; the community of scholars http://dictionary.reference.com/browse/community
A community is a social unit of any size that shares common values. Although embodied or face-to-face communities are usually small, larger or more extended communities such as a national community, international community and virtual community are also studied http://en.wikipedia.org/wiki/Community