In the common collector amplifier, when the input and output signals are compared:

A common collector amplifier, often called an emitter follower, takes its input at the base and its output at the emitter. Because the output voltage closely tracks the input voltage, the input and output signals are exactly in phase. This is a major contrast to the common emitter amplifier, which inverts the signal and produces a 180-degree phase shift. Understanding this difference is crucial for choosing the right amplifier for a specific circuit design. The distractors suggesting a 90-degree phase shift are incorrect because a standard transistor amplifier does not inherently introduce a 90-degree phase lag or lead; such shifts are typical of reactive circuits containing capacitors or inductors.