1. A method comprising: under control of one or more processors configured with executable instructions, receiving a primary keyword inputted by a user and a plurality of requests for retrieving keywords related to the primary keyword received from the user; recording a frequency at which the plurality of requests for retrieving keywords related to the primary keyword are received from the user; selecting a candidate group of related keywords from groups of related keywords corresponding to the primary keyword based on the frequency at which the plurality of requests for retrieving keywords related to the primary keyword are received from the user; and displaying related keywords in the candidate group of related keywords.
1. A method comprising: under control of one or more processors configured with executable instructions, receiving a primary keyword inputted by a user and a plurality of requests for retrieving keywords related to the primary keyword received from the user; recording a frequency at which the plurality of requests for retrieving keywords related to the primary keyword are received from the user; selecting a candidate group of related keywords from groups of related keywords corresponding to the primary keyword based on the frequency at which the plurality of requests for retrieving keywords related to the primary keyword are received from the user; and displaying related keywords in the candidate group of related keywords. 2. The method as recited in claim 1 , further comprising storing the groups of related keywords corresponding to the primary keyword into a cache of a server end.