A drip irrigation hose is a (usually) flat hose that has a row of small holes along one side. Some drip irrigation hoses will have holes all over instead of just one row, but these seem to be far less common. Water squirts out of the holes like tiny fountains up to 2 or 3 feet high, watering the soil and nearby plants. It's similar to a garden soaker hose, except that a garden soaker hose has nearly microscopic holes that water seeps out of instead. Drip irrigation and soaker hoses are often confused; not surprising as they're similar.

Drip irrigation hoses are sometimes called sprinkler hoses

Directions usually suggest placing the hose upside down. The water squirts into the soil, and eventually soaks down and out. Maybe people place the hoses hole side up, and that works too, although you'll have less control over where the water goes.

If you don't lay the hose in a straight line, instead for example snaking it along and through plants, it's usually difficult or impossible to have it perfectly flat. Some of the fountains will probably shoot out at odd angles, so be sure to position the hose to water the areas desired.

Most drip irrigation hoses will water faster than soaker hoses. Often you'll only need have them on about half the time of soaker hoses.

Note that drip irrigation hoses are often used in fairly complex "microirrigation systems," also known as "drip irrigation systems." These can get as complex as you'd like, but a simple drip irrigation hose alone gives you additional flexibility in watering your shrubs, garden, and lawn.