What's the difference between the LifeStyle and polyamory?
Polyamory centres multiple loving romantic relationships. The LifeStyle — also called swinging — centres recreational and social sexual connection within a community of couples and singles, while the primary romantic-partnership identity stays intact. Both are ethically non-monogamous; the dividing line is whether other partners are loved or played-with.
Both polyamory and the LifeStyle are configurations of ethical non-monogamy: outside-the-couple sexual connection happens, but with the explicit consent of everyone involved. Beyond that shared foundation, the two structures organise themselves around very different premises.
Polyamory is centred on the romantic-emotional dimension. Multiple deeply-committed romantic relationships are the structure, not an exception to it. A polyamorous person is oriented toward more than one loving partnership at a time. The shape can be hierarchical or non-hierarchical, kitchen-table or parallel, but the through-line is that partner as a category is plural and the connections are romantic-partnership-shaped.
The LifeStyle is centred on recreational and social sexual connection within a community. The primary romantic-partnership identity — almost always a couple — stays the central commitment. What the couple shares with other LifeStyle participants is sexual and social: parties, clubs, travel, conventions, ongoing friendly community. Other LifeStyle participants are not partners in the polyamorous sense, even when the same couple is seen at events week after week.
The boundary is permeable in practice. Some LifeStyle couples form ongoing close emotional bonds with other LifeStyle couples and find themselves edging into polyamorous territory; some polyamorous people enjoy LifeStyle spaces for the recreational dimension without rearranging their romantic structure. The point of the labels isn't to draw a hard line. The point is that the two communities have built different infrastructure — different events, different etiquette, different language — and people generally find one or the other a better fit for what they actually want.
If you're trying to figure out which configuration fits, a useful test question is: do I want more than one loving romantic partnership, or do I want a shared sexual and social community for me and my existing partner? Both are valid answers. The structures that go with each answer are different.