Everyone who works with the business does not need the same view of it, and the roles reflect that.
The principle
The access a person's work requires. Not less, which produces requests to the owner for routine things, and not more, which puts financial detail in front of people who have no use for it.
What the roles differ on
Chiefly financial detail. Revenue, margins, owner compensation and the full financial picture sit with the roles that need them.
Beyond that: customer records, the ability to change settings, and the ability to invite others.
The specific roles and what each carries are set out in roles and permissions.
Common arrangements
The owner holds full access.
A bookkeeper or accountant needs the financial detail and generally nothing operational.
An office manager needs customers, scheduling and invoicing, and frequently not margins.
Field staff need their own work rather than the business's finances.
Separation is a control as well as a courtesy
The person who enters transactions and the person who reviews the accounts being different people is one of the more effective protections a small business has — see fraud prevention.
Each person gets their own account
Shared logins remove any record of who did what and mean access cannot be withdrawn from one person without withdrawing it from everyone.
Adding someone is done from inviting a team member.
When someone leaves
Access is removed the same day, alongside keys and equipment — see terminations.
Protecting the accounts
Two-factor sign-in is worth requiring on any account with financial access.