Modern landscape lighting is a low-voltage (12V) system. A transformer steps 120V house power down to 12V, then buried cable runs out to weather-rated fixtures. 12V is safe to bury shallow, safe around water features, and doesn't require licensed conduit work.
Fixtures come in categories by job: uplights (aimed up at facades and trees), downlights (moonlighting from a tree), path lights (defining walkways), wash lights (broad soft light on plantings), well lights (buried, aimed up), step lights, and hardscape/deck lights.
The lamps are almost always LED now. LEDs draw a fraction of the power, last 10x longer, and let one small transformer run a much bigger system than the old halogen days.