The DS18B20 (and similar) sensors can be powered in one of two ways:

1. So-called "parasite" power - where the DQ line carries both power and data;

2. "Normal" connection, where power & data are separate.

Which is "simplest" (sic) depends on how you look at it:

1. "parasite" power requires only 2 connections; so the wiring, connectors, etc are "simpler" - but the software is more complex;

2. "Normal" connection requires 3 connections; so the wiring, etc, is more complex - but the software is simpler.