Information and belief refers to a person declaring that he or she is not 100% positive that a particular claim is true, but that it is what he or she has been told, and he or she believes it to be true. Information and belief is often relevant when witnesses are testifying on a witness stand.
If a person intentionally lies about something on the witness stand, this can be perjury. The distinction of information and belief is used to indicate that the witness does not actually know if a claim is true. He or she only knows the information that he or she was given, and believes it to be true. For example, a witness may have been told by a defendant that he or she committed a crime. The witness may not know if this is true, but may give a statement of information and belief about it being true.