low maintenance

What exactly does it mean to be low maintenance in a relationship? Does it mean you never ask anything of your partner? Do you never take long in the bathroom? Do you last a long time between oil changes?

This phrase seems most often used within the context of a love relationship; can it also be used about friends, family members, relatives, coworkers, playmates, acquaintances, and so forth? Do we only think in these terms when it comes to romance? Why is that?
I’d love your thoughts on this.