How can using a hash table instead of a linear list result in greater efficiency? What could possible go wrong? The implementation of a hashtable

Introduction :

Key-value pairs are kept in a data structure called a hash table. The required value is found by computing an index into an array of buckets or slots using a hash function. Many different applications, including databases, caches, and hash maps, use hash tables. A hash table's primary benefit is that it makes data lookup, insertion, and deletion quick.