DFRobot Digital RGB 180-LED Strip (3 Meters)

These are the addressable LEDs, so there is ground, power connection, and then digital signal connection for setting colors and brightness of individual LEDs. You can cut them, and use connectors. That said - this is a terrible deal. You don’t even need to go on aliexpress or something - you can get these on amazon for less than half this price. And these arent even the new hotness as far as speed, color depth, or signal redundency are concerned. The newer versions carry two signaling connections, instezd of one, and can be switched at like 2-5x the rate of these.

awful deal

This is not a good deal at all. You can get more LEDs for cheaper on Aliexpress https://www.aliexpress.com/item/1m-4m-5m-WS2812B-Smart-led-pixel-strip-Black-White-PCB-30-60-144-leds-m/2036819167.html-- the 4m 60 led/m IP67 model is 30% longer, and a third of the price. It'll also likely arrive sooner, even though it's coming from china.