One of the hardest lessons for first-time founders is that controlling a company is not the same as owning most of it. The board of directors makes the decisions that matter most, and board control is allocated separately from shares.
The board hires and can fire the CEO, approves budgets and financings, and signs off on selling the company. A founder who owns a majority of the stock but sits on a board they do not control can be overruled on exactly these decisions, and, in the extreme, removed from their own company. Ownership is about economics; the board is about power.
Early on, founders hold the board. As investors come in, they typically negotiate seats, and a common early structure balances founder seats, investor seats, and an independent seat that tips the balance. The composition, not the arithmetic of shares, is what to watch. Ceding board control before you must is one of the more consequential things a founder can do.
Board seats are negotiable, like any term, and worth defending. Keep the board small early, be deliberate about who fills the independent seat, and understand that each round tends to add investor influence. This is general information, not legal advice; a good startup attorney is worth having on governance terms.
Guard the board like it is the company, because it is.