If you need to load more than 50,000 records in Salesforce, then the Data Loader is your tool of choice. In this lesson, we look at installing and using the Data Loader. We also address when to use the Data Import Wizard vs. the Data Loader.
Export and Import with Data Management Tools - Trailhead - https://trailhead.salesforce.com/content/learn/projects/import-and-export-with-data-management-tools
When to Use the Data Loader - https://help.salesforce.com/articleView?id=when_to_use_the_data_loader.htm&type=5