flyinfinni is right. It's an SMT capacitor. It may be part on a filter circuit - in which case, the motherboard may still work. Or it may be part of a timing circuit, in which case the motherboard won't work. Third possibility is that it is part of some feature that you are not using, in which case, it doesn't matter.
The fact that you had to ask what it is indicates that you will not be able to repair it.
Someone who is good at SMT soldering might be able to fix it.