Concept:
Sprinkler heads distribute irrigation water over the land surface in the form of droplets.
Step 1: Small lawns and gardens require neat and uniform irrigation.
Step 2: Pop-up sprinklers remain hidden below ground level when not operating.
Step 3: During operation, water pressure makes the sprinkler head rise and spray water.
Step 4: After irrigation, it goes back down, making it suitable for lawns and gardens.
Step 5: Therefore, the correct sprinkler head is pop-up type.
\[
\boxed{\text{Pop-up type}}
\]