The Declaration is not a legally binding instrument.
This means that it confers no compulsion to all the rights it contains. When a text is binding this means that States, which have ratified it, have the obligation to respect and enforce the rights enshrined.
Nevertheless, the Declaration contains a series of principles and rights that are extracted from other international instruments on human rights that are legally binding (such as the International Covenant on Civil and Political Rights).
Moreover, the Declaration was adopted by consensus, which means that States have agreed on the text and, therefore, they are committed to implementing it.
For more information, please consult the OHCHR’s website.