What are custom fields?
Custom fields are placeholders/variables to represent contact data that your CSV file contains for each contact. These are variables that can be created/customized to be used along with the contacts data available in imported CSV files like First Name, Last Name, Company, etc.
Click here to know how to create custom fields in your Saleshandy account. Once a custom field is created, you can map it with the CSV file headers when you upload the file to import the contacts. If you want to know how a custom field is used in a sequence, please click here.