Clients are a way to organise the people on your system.
Everyone starts with a single client, which is the business that signed up for Issuebear. We call this the "Your Company". All your support agents will be added under this client, along with any other staff you have.
After that you can create additional clients as needed.
For example, you may provide support for customers at other businesses. You can create a client for each of them, and then create ticket hub user accounts for each customer who needs to create tickets. Users belonging to clients can only see the tickets created by that client, giving you a nice way to provide support to your customers.
Of course if you're only providing internal support, you may not need to add any further clients.
Client settings are found here.