Caption: The Sun's traversal of the ecliptic and the zodiac constellations illustrated by NAAP Applet: Seasons and the Zodiac Simulator.
Left click to rotate the ecliptic, the zodiac constellations, and the celestial axis.
But the zodiac signs are NOT the zodiac constellations.
The zodiac signs are 30° segments of the ecliptic that start with the vernal equinox.
Formally, the zodiac is the set of the 12 zodiac signs.
Informally, the zodiac is also the set of 12 zodiac constellations.
Due to the axial precession, the zodiac signs have moved about 30° west of where they were circa the 1st 1st millennium BCE.
For example, the sign of Aries is about 30° west along the ecliptic from the zodiac constellation Aries and the Sun passes through the sign of Aries about 30 days before it passes through the zodiac constellation Aries (see Wikipedia: Zodiac: Table of dates).