SingleOps allows you to use Client/Customer records like a CRM (Customer Relationship Management) system.
A Client/Customer (terms used interchangeably in SingleOps) is the Customer Account for billing and account management. Each Client has their own profile - eventually synced in Quickbooks (if applicable) - where you can find all associated jobs, invoices, primary contact info, and more. One of those "mores" is the individual Contacts (actual people) that are associated with that client - for example: a spouse, partner, property manager, billing department, etc. These are Contacts in SingleOps.
To add Contacts to a client's profile, you can do this(1) from the Client's record or (2) on the job itself.
On Client/Customer: Simply select the client to which you would like to add the contact(s). Once you're editing the client you will see a "Contacts" tab that will allow you to add and manage contacts.
On Job: Under Additional Options, where you would find tax location and/or Sales Rep, there is a place to add a primary contact to the job. Doing so will also add that contact to the Client's profile.
The Contact Form allows you to enter the Client's name, the type of contact, phone, and email. If you would like this contact to have access to the client portal where they can view all open proposals and invoices for the client, you would check the box in that column. You can also add custom inputs on the contact form to collect additional information.