The term 'free love' these days is usually interpreted as a reference to sex, especially when connected to the 1960s. It was a time of sexual liberation and experimentation, when contraception became more available and barriers broke down. For some hippies, having sex with complete strangers was as normal as shaking hands with them, and the threat of sexual diseases wasn't yet known or understood.
The community at Woodstock definitely loved each other, but that didn't always mean they were taking each other to bed. As seen here, people who'd never seen each other before in their lives would often greet each other with a warm embrace like they were long lost family, accepting them within the spirit of love and universal peace that the festival embodied. Nobody had to feel alone at Woodstock. Everybody was welcome. We imagine the drugs probably helped, all the same.