Subscriber = play have you have been since launch and get a max of 500 Cartel Coins per month free with subscription.
F2P = play the game from level 1 - 50 without a subscription, but you will not be able to do side quests you will be limited with PVP and flashpoints i think 2 rounds of each per week. if you want more you have to use cartel coins that cost real cash.
If you are a subscriber and able to afford $0.50 per day then you would be wise to continue.
Thanks for the answer, and yes i can afford it, i have been since the game launch =)