It’s a set of resistors plus maybe some accessories (breadboard, wires) that lets you practice different resistor connection types:
 
Series connection
Parallel connection
Series-Parallel combinations
 
These kits are often used for learning how to calculate total resistance, voltage drop, current flow, and understand resistor behavior in circuits.
 
How to Connect Resistors
 
1. Series Connection
Resistors connected end-to-end, one after another.
Current flows through each resistor sequentially.
Total resistance: Rtotal=R1+R2+R3+…R_{total} = R_1 + R_2 + R_3 + \dotsRtotal​=R1​+R2​+R3​+…
Example:
 
---[R1]---[R2]---[R3]---
2. Parallel Connection
Resistors connected across the same two points.
Voltage across each resistor is the same.
Total resistance: 1Rtotal=1R1+1R2+1R3+…\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \dotsRtotal​1​=R1​1​+R2​1​+R3​1​+…
 
Example:
 
|---[R1]---| ---| |--- |---[R2]---|