A single problem with the Linux sound system: Find recording software that not only records microphones but also system sounds

A single problem with the Linux sound system: I beg you to read the Linux general technology-Linux technology and application information, which is not only a microphone but also a recording software. Some time ago, I searched the screen recording software in Linux and found that some of them could only record microphones. If I put a piece of music, the video would not be recorded, later, I wanted to use a recorder to record the background sound, but I could only record the microphone. The same was true for audacity, and I was not allowed to enable other sounds during the recording. In this case, the Linux sound system is still quite problematic. No wonder the Community has criticized sound system developers before. However, when I recently used ubuntu10.04, I found that the system's totem player does not occupy the sound, and has a pre-reading function for the music, so I can hear the music after hovering the mouse over the music file for a few seconds, you do not need to open it to prepare the listener directly. At the beginning, I thought it was a noise. I was excited to find this small change. I need to know that when I was watching an online video, other players didn't want to open it. In terms of sound, I have very few configurations, which are all default. I am eager for software that can record the voice of the system, that is, I can play a song and play a game. Everyone knows.