What are the distinctive sorts of accumulations in Salesforce Apex?

Hello Piyush,

Accumulations are the sort of factors which can be utilized to store numerous number of records (information).
It is helpful in light of the fact that Governor Limits confine the quantity of records you can recover per exchange. Henceforth, we can utilize accumulations to store various records in a solitary variable characterized as sort gathering and by recovering information as accumulations. Accumulations are like how exhibits function.
There are 3 accumulations composes in Salesforce:

1.Records
2.Maps
3.Sets
We utilize maps to store information as key-esteem sets, where every one of a kind key maps to a solitary esteem.
Sentence structure:

Map<String, String> country_city = new Map<String, String>();