Charms come in different forms. They can be something we can wear (mostly like bracelets), or something we can display (such as figurines). A charm is used either to attract positive energies or deter negative ones. This kind of belief in charms is commonly seen in Chinese or Eastern cultures, more often in the field of astrology.
Honestly, I am caught in the middle. I don't claim myself as a strong believer of these kinds of stuff. But it really amazes me and catches my interest.
And as with any other superstitious belief, there is nothing wrong if we follow certain rules or use some objects as charms.
It is still our faith that counts.