Material Properties:

* Resistance: This is the inherent opposition to the flow of electricity within a material. Different materials have different levels of resistance. Conductors (like copper and silver) have low resistance, while insulators (like rubber and glass) have high resistance.

* Resistivity: This is a material's intrinsic ability to resist electrical current. It's a property of the material itself, independent of its shape or size.

* Temperature: For most materials, resistance increases with temperature. This is because the atoms in the material vibrate more at higher temperatures, making it harder for electrons to flow through.

Geometric Factors:

* Length: The longer the wire, the greater the resistance, as electrons have to travel farther.

* Cross-sectional Area: The thicker the wire, the lower the resistance. This is because there is more space for electrons to flow.

* Shape: The shape of a conductor can also affect resistance. For example, a thin, long wire will have a higher resistance than a thick, short wire.

Other Factors:

* Impurities: Impurities in a material can scatter electrons and increase resistance.

* Frequency: At high frequencies, the skin effect can cause current to flow primarily on the surface of a conductor, effectively reducing the cross-sectional area and increasing resistance.

* Magnetic Fields: A changing magnetic field can induce currents that oppose the flow of the original current, slowing it down.

In summary, any factor that increases the difficulty for electrons to move through a material will slow down the electrical current.