Choosing Your Faction:
You'll have to choose between two factions when you choose to play Ingress. You can be the Enlightened who fight believing their actions will uplift humanity and bring about the next chapter in human evolution, or you can be of the Resistance which believes that it is protecting humanity from Shaper ingression and preserving humanity's freedom.
These two factions are the opposing "sides" or "teams" in the game. The Resistance is represented in the game by the color blue, and the Enlightened by green. In some areas, the Resistance are jokingly referred to as "smurfs". Similarly, the Enlightened are referred to as "frogs" or "toads", while the lower-level players are referred to as "tadpoles".
Often, in playing the game, the factions will come together and cooperate for the sake of gaining more points and levels. Niantic not only supports such activity, it encourages and frequently helps to arrange such activities.
It's not unusual for groups to get together at large venues and take turns overtaking portals. This helps both teams to grow and flourish. It's also a great time for newer players to learn how the game works and how to overtake portals and deploy resonators. It's also a great time to honor fallen heroes and share portal keys and gain other important items to deploy or save for future game play.
It's great fun for family members to be on different sides. It can keep the game interesting and help to balance out a specific area that may be leaning more toward one faction than another.
More portals can be submitted as desired. It takes anywhere from a few days to a few months for new portals to be accepted depending upon the area that a new portal is being submitted.
It's also fun to visit other portals when on vacation or simply taking a trip to town. Stay in communication with your team by participating on the forum and in your communications device and gather a group together to take over and area and turn the field blue or green.
Although I've never considered changing factions, I have heard that you can change to the other side (come to the dark side we have cookies?) one time should you choose to change sides in the game.