Polyamory is the practice of having multiple, open, honest emotional and sexual relationships. This is a pretty broad umbrella, which covers relationship styles that vary from group marriage to those that look very much like "dating". Additional details of what you may expect to find and not find under this topic:

• This section is not intended to cover swinging, which is generally perceived as a style of multiple sexual relationships rather than a style of multiple romantic relationships. For more information on swinging, see: Society: Sexuality: Activities and Practices: Swinging.
• This section is not intended to cover affairs or 'cheating' either.
• This section is not intended to cover group sex.

There is generally little overlap between the community that uses the term "polygamy" and the community that uses the term "polyamory". There is therefore a separate listing for polygamy under Alternative Lifestyles : Polygamy, although the actual dividing line is arguable.