Insertion in Hashtable

Can you explain hash function once again.I didn,t understood that

hello @shubhangis248
let say abcd is the string then what that hash function doing is this->

( a + b * 27 + c * 27^2 + d* 27 ^ 3 ) mod table size

note here ascii value will be taken in place of a b c d

along with this we taking mod with table size to avoid overflow and to make sure that idx always come in range of table size