看望 (kàn wàng) means 'to visit (someone)' with a caring or polite tone — it's used when you go to see someone who is ill, elderly, or to show respect. It's more polite and specific than the general 看 (kàn), which can also mean 'visit' but is less warm. 探望 (tàn wàng) is similar but more strongly implies visiting someone who is sick or elderly.