Why can only one template be active at a time, and how do you switch?

Only one template is active at a time because the storefront serves a single, coherent customer experience — having two themes live simultaneously would be ambiguous. You can install multiple templates and switch the active one (an activate action), so changing your storefront's look is a matter of activating a different installed template. This lets you stage, compare, or seasonally…

Only one template is active at a time because the storefront serves a single, coherent customer experience — having two themes live simultaneously would be ambiguous. You can install multiple templates and switch the active one (an activate action), so changing your storefront's look is a matter of activating a different installed template. This lets you stage, compare, or seasonally swap templates while always presenting exactly one to customers.