Experience and Reputation are resources used to unlock vehicle upgrades and to advance vehicle progression in Armored Warfare.
Experience
Experience (formerly known as "Reputation"[1]) or XP are earned by vehicles individually via battles, and they are in turn used to unlock vehicle upgrades or other features, such as commanders and retrofits. Once unlocked with Experience, some vehicle upgrades, particularly modules, have to be purchased with 
Credits in order to apply the said upgrade to the vehicle. Experience earned from battle also slowly fills up a progression vehicle's progression bar.
Experience is tied to the vehicle that it is earned from, and they cannot be transferred directly for use to other vehicles. However, vehicles continue to earn Experience even after filling up their own vehicle progression bar. Once that happens, any further experience earned from battles will be pooled up in a separate resource colloquially called 
Locked Experience, which can then be converted into Reputation with 
Gold.
Experience earned per match can be further boosted with Premium Time (also known as Premium Account), boost tokens, insignia tokens and first win of the day multiplier for each vehicle. Premium vehicles and progression vehicles with Battle Hardened status, as well as some premium commanders with "Combat Experience" skill can also increase the experience earned in each match.
Reputation
Reputation (formerly known as "Global Reputation"[1]) is essentially Experience that is not tied to any specific vehicle, and it can be used the same way Experience is used on any vehicles that need Experience to unlock new upgrades, not just on the vehicle that was earned from. Reputation can be earned from battle as a separate resource from Experience, and such gain can be increased with boost tokens and insignia tokens. Alternatively, one can also obtain Reputation from Loot Crates drops, log-in bonus, or converted from Locked Experience with Gold.