A stakeholder is any person or entity who holds an outstanding security in your company (shares, nominee shares, options, ESOP, convertible note, or shareholder loan).
If there are any entities that are part of one or more security, they will only be counted towards your stakeholder total once. Orchestra also excludes any historical stakeholders from this count (eg. a shareholder who has since sold all their shareholdings).
Administrator and service provider accounts (such as those for your lawyers and accountants) do not count as stakeholders.
If you had an employee who is a shareholder in the company, but also participating in an ESOP scheme, this would count as a single stakeholder, even though they hold two different types of securities.
If an investor is a shareholder under their name as an individual (eg. Bob Clarke), but also has a shareholding under a separate company entity they're also part of (eg. Bob Clarke's Lightbulbs Limited), then they would be counted as two separate stakeholders.