Often used interchangeably, the terms 'baseboard' and 'trim' mean different things.
The Difference Between Baseboard and Trim, for Finish Carpentry:
Baseboard trim is also referred to as baseboard molding, and molding is another form of trim. Other popular forms of trim include:
Window Casing (Window Trim)
Door Casing (Door Trim)
Panel Molding / Wainscoting
Finally, many pieces are designed for trim can be incorporated in baseboard work. They can include: base caps, stop blocks, plinth blocks, ornamental molding, quarter round (shoe mold), and more.