An error is a human error (design, interpretation coding) which results in defect (affectionately known as a bug as developers and testers tend to have problems with words of more than one syllable)
Errors are normaly detected as issues or observations and do not become defects until they have been analyzed
By universal definition there is no difference. The culture and environment of where you work may allow for different definitions of each of them though. The definitions as set forth by your company is what you must adhere to while you are employed there.