What is the difference between 'bit rate' and 'throughput'?

According to the AN1200.22 LoRa Modulation Basics, the bit rate is calculated by sf*BW/2^sf, which can reach a few kbps.
However, when I divide the received data by the total running time of the program to obtain the average throughput, the value is far less than the above magnitude.
Do I confuse two different concepts?

Multiple bits can be used to represent a data bit.
So generally, bit rate is larger than throughput.