This video covers a particular type of transistor known as the Bipolar Junction Transistors (BJTs). These are more commonly used in analog applications like amplification and signal processing rather than digital logic (though they can be used in specialized digital logic circuits).
Today, field effect transistors (FETs) reign supreme for most IC applications such as CPUs and digital logic as they're more scalable and efficient than BJTs and have a very different structural design.
Today, field effect transistors (FETs) reign supreme for most IC applications such as CPUs and digital logic as they're more scalable and efficient than BJTs and have a very different structural design.