What does the latter power amplifier mean?

What does the latter power amplifier mean? The rear stage power amplifier, commonly known as the pure rear stage, is a device that simply enlarges the 'front stage' audio signal to provide sufficient power to drive the speaker to sound (Always connected before the speaker). So what is the 'front level' mentioned here? It is a device that provides appropriate audio level signals and adjusts sound quality ( Commonly known as preamplifier, connected between sound source and power amplifier). How to connect the rear power amplifier? The front amplifier is generally connected to the pure rear power amplifier. The front output is connected to the input end of the rear stage, and the rear stage is connected to the speaker. The preamplifier is an amplification voltage, the pure rear power amplifier is an amplification current, the preamplifier is a link device between various sound source devices and power amplifiers, and the output signal level of the sound source devices is relatively low, the power amplifier cannot be pushed to work properly, and the preamplifier plays the role of signal amplification. The characteristics of the rear stage power amplifier the input signal of the rear stage is very simple, that is, to undertake the output of the front stage. But the load at the back level is the horn, which is what makes many audio fans and even magazine reviewers uncertain. The latter stage is the front stage load and is a high impedance load; The horn is a rear load and a low impedance load. It looks similar, only one word is missing, but one high and one low impedance makes it easy to push or push. The current stage is connected to a high impedance rear stage, which mainly provides an tangent output voltage because the rear stage expander. Summary: power amplifier is generally divided into front-level power amplifier, rear-level power amplifier and combined-level power amplifier. The merging machine integrates the front-level and rear-level machines. The front stage is used to initially amplify the signal and adjust the volume; The latter stage is to enlarge the signal from the previous stage to push the speaker. Usually we use the front and back levels together, which is better than the merge level? If the price is similar, the individual recommends a combination of the previous level + the latter level, instead of choosing the merge level.