Credits - Obtained by purchase with real world money via credit card or paypal under the Black Market menu by selecting "Buy More Credits" or obtain for free by watching videos or downloading the suggested application/game under "Earn Free Credits"
Supplies - Obtained through purchase using credits, Outposts, dueling or by Scavending nearby locations under the the "Investigate Nearby" menu option. Supplies are used to upgrade weapons and armor as well as used to repair safehouses.
Cash - Obtained through purchase using credits, dueling, Outposts, Hunting evil zombies or by Scavaging an area unlocked by lock picking. Cash is used to purchase new weapons, armor, dueling items, and misc supplies. Cash is also used to upgrade your safehouse and is told to make the world go around.
Outposts - special locations established which generate either cash or supplies depending on your selection. Outposts which generate supplies are purchase with cash and those that generate cash are purchased with supplies. The amount of outposts you can have without penalty is based on your trader level and is recommended that you only have as many outposts are your trader level to avoid penalty. To collect from your outposts simply select "Manage outpost" from the main ingame menu. From this menu you can sell outposts, upgrade outposts, see the time left remaining before you can collect from them again and their distance from your currect location and amount that can be collected from each. It should be noted that there are 3 types of penalties that can reduce the amount collect from each outpost which include: Distance penalty, Late Collection Penalty and Max outposts Penalty.