How to Remove a White Background From an Image
CutMyBG
A white background looks empty on a white page and obvious everywhere else. Removing it means those white pixels become transparent, not a slightly different white.
White paint and transparency are different
Many product photos and logos are exported on white. The white is real image data. Putting that file on a gray or colored layout shows a white box. A transparent PNG does not.
Subjects that are also white
This is the awkward case: a white shirt, a white bottle, or white text on a white background. The model has to tell the object from the backdrop using edges and shading, not the color white alone. If the object has no visible edge, part of it can disappear with the background. Preview before you download, and prefer a source where the edge is visible.
Shadows on white
Soft gray shadows on a white sweep are often removed with the background. That is useful for a flat catalog image and less useful if you wanted the object grounded. Product photo guidance covers that choice. Logos on white are covered in removing a background from a logo.