Project Fi is cheaper and more flexible than most wireless plans

Google is already an Internet Service Provider and a pay-TV operator. Now it’s expanding to become a wireless carrier as well.

Google unveiled Wednesday a new cell phone service dubbed Project Fi, which offers the same basic functionality as traditional wireless carriers, such as voice, text and Internet access, at a lower price than many common plans.

Here’s a primer on everything you need to know about Google’s Project Fi:

What exactly does Project Fi offer?

Project Fi offers a basic cell phone plan that includes unlimited domestic talk and text and unlimited international texts for $20 per month. International calls will cost $.20 per minute. Subscribers can add a monthly allotment of 1GB of data for $10 month, and increase the allotment by $10 per gigabyte.

One thing that makes Fi different from many mainstream carriers is that any data a customer doesn’t use shows up as a credit on their next bill — each 100MB is worth $1. There are also no overage penalties, as extra data use is charged at the same rate as data that is part of the plan. And, in a nice plus for international travelers, mobile data costs the same $10/GB in more than 120 countries.

How will Project Fi differ from what traditional wireless carriers offer?

Google’s service will switch between different high-speed wireless networks operated by Sprint and T-Mobile, depending on which is stronger in a given area. In addition to regular cellular coverage, phones on Project Fi will switch to Wi-Fi networks when available to place calls and access the Internet without using up customers’ data plans.

Using Wi-Fi for voice service is becoming an increasingly popular strategy in the telco industry — Cablevision recently unveiled a cell phone service that is entirely reliant on Wi-Fi connections and costs $30 per month.

What do I need to get Project Fi?

Right now, you can only use Project Fi with a Nexus 6, Google’s flagship Android phone. The Nexus 6 costs $649 for the 32GB version. Unlike traditional carriers, Google isn’t offering a subsidy on the phone in exchange for a two-year contract commitment (Project Fi is contract-free).

However, customers can pay for the device over the course of two years if they pass a credit check. And if you already own a Nexus 6, it’ll work on Project Fi.

How is Google able to build the infrastructure to offer cell phone service?

Google isn’t building its own cell phone towers for Project Fi. Instead, it operates on networks already operated by Sprint and T-Mobile. The big wireless carriers already make lots of money by effectively renting access to their networks to smaller carriers, who then resell that service to consumers using different branding.