How can I use the standard objects such as account, contact, and opportunity for managing the relationship?

 In the context of Salesforce, to achieve this particular Salesforce, you can use the standard objects such as account, contact, and opportunity and possibly can create custom fields or objects for the requirements of additional. Here is the scenario given:-

Managing relationship

You would need to use the standard “Account” object for representing both customers and even suppliers.

You should create a custom field on the “Account” object for categorizing them as customers or suppliers.

// Example of a custom field on the Account object to categorize as Customer or Supplier

Public class AccountExtension {
    Public static void categorizeAccount(String accountId, String accountType) {
        Account accToUpdate = new Account(Id = accountId, Account_Type__c = accountType);
        Update accToUpdate;
    }
}

Tracking sales process

You can use the object of “opportunity” for the task of tracking the sales process for products and services.

You can customize the opportunity object by the technique of adding the customs fields for specific product details.

// Example of a custom field on the Opportunity object for tracking product details

Public class OpportunityExtension {
    Public static void trackProductDetails(String opportunityId, String productDescription) {
        Opportunity oppToUpdate = new Opportunity(Id = opportunityId, Product_Description__c = productDescription);
        Update oppToUpdate;
    }
}

Building relationships

You can use the standard “contact” Object for the task of associating individuals with both customers and suppliers. You can use the lookup finds on the “contact” object for the task of linking them to the related “Account” and “opportunity”.

// Example of a custom lookup field on the Contact object to associate with an Account
Public class ContactExtension {
    Public static void linkContactToAccount(String contactId, String accountId) {
        Contact conToUpdate = new Contact(Id = contactId, AccountId = accountId);
        Update conToUpdate;
    }
}