Cloning

Clone	DeepClone
If a list is cloned, it duplicates it and has reference.	If a list is DeepCloned, it duplicates and doesn’t have any reference.
Primitive data types are supported.	Primitive data types are not supported.
Parameters: Not applicable	Parameters: Boolean opt_preserve_id – Whether cloned sObjects records ids are maintained. Boolean opt_preserve_readonly_timestamps– Whether cloned sObjects records read only system fields like createdDate, LastModifiedDtate, etc are   maintained. Boolean opt_preserve_autonumbe– Whether cloned sObjects records auto number fields are maintained.
Sample Code: Account Account1= new Account(Name='Test1'); Account Account2= new Account(Name='Test2'); List<Account> AccountList = new List<Account>{Account1, Account2}; List<Account> listDuplicate = new List<Account>(); listDuplicate = AccountList.clone(); AccountList.get(0).Name = 'Testing1'; system.debug(AccountList.get(0).Name + ',' + listDuplicate.get(0).Name); Now AccountList.get(0).Name and listDuplicate get(0).Name will be ‘Testing1’. listDuplicate.get(0).Name = 'Testing2'; system.debug(AccountList.get(0).Name + ',' + listDuplicate.get(0).Name); Now AccountList.get(0).Name and listDuplicate get(0).Name will be ‘Testing2’.	Sample Code: Account Account1= new Account(Name='Test1'); Account Account2= new Account(Name='Test2'); List<Account> AccountList = new List<Account>{Account1, Account2}; List<Account> listDuplicate = new List<Account>(); listDuplicate = AccountList.deepClone(); AccountList.get(0).Name = 'Testing1'; system.debug(AccountList.get(0).Name + ',' + listDuplicate.get(0).Name); Now AccountList.get(0).Name will be ‘Testing1’ and listDuplicate get(0).Name will be ‘Test1’. listDuplicate.get(0).Name = 'Testing2'; system.debug(AccountList.get(0).Name + ',' + listDuplicate.get(0).Name); Now AccountList.get(0).Name will be ‘Testing1’ and listDuplicate get(0).Name will be ‘Testing2’.