If you run one market you will barely notice it. If you run several, markets keep each branch's work separate while the business stays one company.
What a market scopes
A market has its own customers and jobs, its own receivables, price book and tag categories, its own phone line and its own service-area ZIP codes. Two branches can price the same work differently because their costs differ. The name is yours: Market, Region, Division, Branch.
Account and job numbers are company-wide, so a number is never repeated across markets and moving work between them causes no clash.
Create and manage
Settings, Company, Markets (owner or admin, team workspace). Each market shows a status: Ready, Needs setup, Couldn't check or Archived, a list of what is left with a link to each setting, and the people assigned to it. With a single market the row is Market name, and Add a market starts the second one.
Who sees which
Assign people to a market from its People section (Assign) or from the person's page. Owners and admins see every market. A person sees only their markets' customers, jobs and money, and owners switch markets from the header and can search across all. Drawing-specific access for outside viewers is set on the drawing.
An owner uses the market switcher to see another market's drawings, schedule and money.