The difficulty electrons encounter as they move through a circuit is called resistance.

Here's why:

* Resistance is a property of a material that opposes the flow of electric current.

* Think of it like friction. Just as friction slows down a moving object, resistance slows down the flow of electrons.

* The higher the resistance, the more difficult it is for electrons to flow.

Here are some important concepts related to resistance:

* Ohm's Law: This law states that the current flowing through a conductor is directly proportional to the voltage across its ends and inversely proportional to the resistance.

* Resistivity: This is a material property that determines how much resistance a material will have for a given length and cross-sectional area.

* Factors affecting resistance: Resistance can be affected by the material's type, length, cross-sectional area, and temperature.

Let me know if you have any other questions about electricity!