htab_hash() returns some hash "h", which is an index in the hashtable pointing to a list of key-value pairs whose keys all hash to "h". there may be several key-value pairs for a single hash, because collisions happen. this is illustrated well here: http://upload.wikimedia.org/wikipedia/commons/thumb/d/d0/Hash_table_5_0_1_1_1_1_1_LL.svg/500px-Hash_table_5_0_1_1_1_1_1_LL.svg.png

in the picture "John Smith" and "Sandra Dee" both hash to 152 which points to a list containing them both