The left and right pictures are typical connections of NPN and PNP triode switches. There is only one difference between pull-up and pull-down resistors. If it is driven by a signal from GND to VCC, the left picture can be used. If it is driven by strong and weak current, select the right picture.
NPN is suitable for low-end driving, and PNP is suitable for high-end driving. The same is true for similar NMOS and PMOS. Therefore, in order to obtain the corresponding control potential difference, it is easier to get an on signal by putting the emitter of the npn to ground. If you connect the collector of npn directly to vcc, then you need a signal above VCC or even VCC to turn on, which is inconvenient to drive, and more importantly, with the change of voltage on the load, your Ib is unstable. So generally speaking, the low end is off at the low end and the high end is on the high end. Are there any special circumstances? Yes, for example, npn adds a bootstrap circuit at the high end to maintain a stable ib. No discussion for now.