Adafruit NeoPixel LED Strip with 3-pin JST Connector - 1m comes with three wires, each 30 cm long, connected to a 1-meter reel of LED strip. The other end of the strip is closed. The wires are color-coded for easy identification: black for ground, green for signal, and red for 3-5VDC power. These strips use SK6812 LEDs, so you don't need an inline resistor, and they can work with logic levels as low as 3V.
NeoPixels are addressable LEDs, which means that with 30 RGB LEDs per meter of strip, you can individually control 30 RGB LEDs! You can set the color of each LED's red, green, and blue components with 8-bit PWM precision (24-bit color per pixel). LEDs are controlled by cascaded shift registers along the strip, so you can cut the strip to shorten it if needed. Only one digital output pin is required to send data. PWM is embedded within each LED chip, so once you set the color, you can stop communicating with the strip, and all LEDs will continue to PWM for you.
The strip is made of flexible PCB material and comes in a weather-resistant case. You can easily cut it with wire cutters. Of course, you can also connect them end-to-end to make longer strips.
To power these strips, you should use a 3-5V DC power supply, and do not exceed 6V, or you can risk damaging the entire strip.
These LEDs use a maximum of approximately 4.8 Watts per meter (~1 Ampere @ 5V). The maximum rating assumes all LEDs are at full white, typically actual current for colorful design is less than 1/3 of the maximum.