A customer is an individual who is either enrolled in the org’s loyalty program or subscribed to the org’s newsletters. An org is a business firm that is registered with Capillary - a retail store, hospital, pharmacy, restaurant, or any other firm.
Customer Lookup is an extension to normal customer APIs where instead of fetching or updating details using customer ID, you can use registered identifiers like mobile number, email ID, external ID, card number and so on in /customer/lookup.