Define Batch Apex Class

global class UpdateAccountNames implements Database.Batchable<sObject> {
    global Database.QueryLocator start(Database.BatchableContext BC) {
        // Collect batches of Account records to be processed
        String query = 'SELECT Id, Name FROM Account';
        return Database.getQueryLocator(query);
    }
     
    global void execute(Database.BatchableContext BC, List<Account> accList) {
        // Process each batch of records
        for(Account acc : accList) {        
            // Update the Account Name 
            acc.Name = acc.Name + ' - Updated';
        }
        // Update the Account records
        update accList;
    }
     
    global void finish(Database.BatchableContext BC) {
        // Perform post-processing operations if needed
    }
}