How does the control grid in a triode amplify an electrical signal?

In a triode, the control grid amplifies an electrical signal by acting as a gate that modulates the flow of electrons between the cathode and the anode.12

The process functions as follows:
* Biasing: The anode is maintained at a positive potential to attract electrons emitted by the heated cathode. The control grid, positioned between them, is typically held at a negative potential.32
* Modulation: Because the grid is an open-mesh structure, it allows electrons to pass through to the anode. However, because the grid is negatively biased, it exerts an electrostatic force that opposes the flow of electrons.123
* Amplification: Small variations in the voltage applied to the grid significantly alter this electrostatic barrier, allowing more or fewer electrons to reach the anode. Because the grid is closer to the cathode than the anode is, these small changes in grid potential can control large fluctuations in the anode current, resulting in an amplified output signal that mirrors the input.132