In cell phone industry, these terms are used to tell whether a cell phone will work with sim cards from different carriers. For example, if the GSM phone is unlocked it will work if you put an active T Mobile or AT&T SIM card in it. If it is locked to AT&T you can only use a AT&T SIM card, likewise, if it is locked to T Mobile you can only use it with T Mobile. Phones are generally locked, if you want an unlocked phone, look for one that specifically says it is unlocked.
In wireless scouting camera industry, unless specified, they are "Unlocked". This means you can take your wireless scouting camera to any compatible carrier to activate your camera if the carriers you are going to use are willing to do it for you. Activating your camera means:
Activating a SIM card (AT&T or T-mobile), when you have a GSM/2G or UMTS/W-CDMA 3G camera.
Activating your actual device (Sprint or Verizon), when you have CDMA2000 camera.