拜访 is more formal and respectful than 访问 (fǎngwèn, to visit - neutral/official) or 看望 (kànwàng, to visit - caring/warm). Use 拜访 when visiting someone you respect.
culture
During Chinese New Year, 拜访亲友 (visiting relatives and friends) is a major tradition. The first few days after New Year's Eve are dedicated to visiting family in order of seniority.
