Builders usually work on one or two jobs at a time. They might have a partner, or a family member, or several employees/journeyman that they work with regularly. They fold all the work of management into their day, which often extends into evenings and weekends. They are intimately involved in the carpentry work, and oversee the trades to varying degrees. They tend toward keeping things simple. Focused on the work at hand, they might lose sight of long-lead items that need to be ordered in advance. If they have a question about a construction detail it might only be discovered on site, rather than during a drawing review prior to the work. Generally their estimates run a page or two, covering the work in broad strokes, including their labor, a materials estimate from the lumber yard, and estimates from major subcontractors.
Managers are capable of running several and more complex jobs at a given time. They have a lead carpenter/site manager at each job-site. Depending on workload, they might subcontract major portions of the work such as rough framing. They spend a lot more time in the office and on the phone than Builders. When they visit a job site they are less likely to pick up a hammer, but they should still have a wealth of experience in the field, and do get more closely involved when questions arise or special coordination with sub-trades is required. They tend to see further down the road, and should keep customers on track with timely decisions. They also tend to spend more time reviewing plans and establishing the logistics of a project prior to each stage of work. Generally, their estimates are quite detailed, with multi-page spreadsheets and line item figures incorporating data from previous jobs. In general there is an added cost to this level of oversight, which can be well worth it for complex projects.