AWT was there first; Swing is much newer, and builds on AWT.
They don't do the same work at all. AWT provides lowest-common-denominator access to the native window system's widget set. Swing provides a set of much more complex components which are drawn entirely from
Java. Whereas AWT has the native platform's look-and-feel (well, sorta,) Swing implements pluggable platform-independent look-and-feels.