If you have a question，you may want to get a quick answer online.Some technology companies are working to make this come true by developing chatbots.They are computer programs that can communicate with people by phone，on messaging apps or on websites.
Chatbots can look up information，answer frequently（经常地）asked questions and collect information from users.They can also be used for online shopping to help people decide what to buy.
There are two kinds of chatbots：open and closed.A closed chatbot may or may not use Al （人工智能）to understand messages from users.An open chatbot uses Al both to know what people want and to create a reply.Open chatbots are able to learn from their conversations and then improve their ability to communicate over time.This means that open chatbots can answer a wider range（范围）of questions, compared with closed chatbots.
One important advantage of chatbots is that they are available all the time，even at midnight.What's more，one chatbot can serve many users at once.This means that people can get answers quickly instead of waiting for the reply of a human agent.
▲ Someone has to program the chatbots at the beginning and train them.Sometimes，open chatbots can't give answers to certain questions.Besides，many people prefer speaking to a human rather than a chatbot.
