It integrates two 47 kOhm resistors — one in series with the base (R1) and one between base and emitter (R2) — so you can use it as a simple switch or inverter without external bias components.
Built-in resistors save board space and BOM count
The 47 kOhm base resistor (R1) and 47 kOhm emitter-base resistor (R2) eliminate the need for two external passives per transistor. That matters when you are populating a dense PCB with multiple switching stages — fewer components, fewer placement errors, and a cleaner layout. The pre-biased configuration also guarantees a defined off-state with the base pulled low through R2, which simplifies the drive design.
That is a widely used footprint that pick-and-place machines handle without special tooling.