How does facial recognition technology work?

SAN FRANCISCO (KGO) -- There are two different types of facial recognition technologies; one is the technology built into the iPhone and the other is the facial surveillance technology.

"The government is not going to ask us to come in and suddenly measure our faces. Instead what's going to happen is that they take database on photos they already have and feed it into a computer program and then they take photos of us from CCTV cameras and measure it against that database," explained Ian Sheer, Executive editor for CNET.

RELATED: San Francisco bans use of facial recognition technology by local enforcement

San Francisco became the first major city in the U.S to ban this type of facial recognition by police and all other municipal agencies.

"It tries to identify who you are based on what it thinks it knows about you. For example; if it has a photo of you from the past it will try to match that up against what it sees now, and say oh this is the same person. There are other technologies as well that use little dots of light and infrared and all that type of stuff. Basically, it's about identifying you versus what it thinks you are already the system"

With an 8-1 vote, the board of supervisors agreed on more accountability for surveillance technology under what they called the "Stop Secret Surveillance Ordinance."

Supervisor Aaron Peskin authored the ordinance and said, "When personal information of innocent members of the public is shared with third parties in ways that would make anyone uncomfortable. When marginalized groups weather because of the color of their skin, their religion, national origin or sexual orientation or gender identity are tracked."