What they are and how they work
The image lists 30 resistors in total, in 220 Ω, 1 kΩ and 10 kΩ values. It does not state how many of each value are included. Resistance is measured in ohms; 1 kΩ means 1,000 Ω. A resistor limits current and develops a voltage drop when current flows through it.
Coloured bands identify resistance and tolerance. A nominal value need not exactly match every measurement. These ordinary resistors have no polarity, so reversing their leads does not change their function. Their power rating cannot be determined from the kit photograph.
What we can use them for
- Limit current through an individual LED or each RGB channel.
- Define an input's resting state with a pull-up or pull-down connection.
- Build a voltage divider and compare its input and output voltages.
First exercise
Sort the resistors by their bands, then measure them with a multimeter while disconnected from power and other circuit paths. Record the quantity of each value. For a simple LED experiment, calculate resistance from the supply, LED forward voltage and a chosen small current. Do not select a value from LED case colour alone.
Handling notes
Neither 220 Ω nor another value suits every circuit. Check current, resistor power and GPIO limits. A voltage divider does not replace a power supply for a varying load. Always measure resistance with power disconnected.
Source: SparkFun — Resistors.