Answer
Field history tracking in Salesforce allows you to track changes made to a record's fields. To enable field history tracking, you go to the object settings, select the fields you want to track, and enable history tracking. Salesforce allows you to track up to 20 fields per object. The changes are stored in a related history object (e.g., Account History or Contact History). One key limitation is that the history data is stored for 18 months in Salesforce, after which it is archived or deleted. Additionally, only certain field types can be tracked, such as text, picklist, and date fields, but not formula or auto-number fields.