The "Flag of Luxembourg Belgium" refers to an erroneous designation. The correct name should be either the Flag of Luxembourg or the Flag of Belgium, as these two nations are separate entities with unique flags.
The Flag of Luxembourg consists of three horizontal stripes: a red stripe on top, a white one in the middle, and a bottom stripe that alternates between white and blue.
On the other hand, the Flag of Belgium is a tricolor, divided vertically into equal parts; the left half is composed of five horizontal stripes (from top to bottom: black, yellow, red, black, and yellow), and the right half is white.
It's important to note that while there may be similarities between the flags of neighboring countries, Luxembourg and Belgium have distinct national symbols that reflect their individual histories and cultures.