The senior Parliamentary officials who advise the Presiding Officers and Members in the correct operations of Parliament as determined by the Standing Orders. They also maintain the formal record of proceedings (the Votes and Proceedings), and manage the daily affairs of the Parliament.
The presiding clerk is the person who conducts the business and who formulates the "sense" of the meeting. A business meeting may also have recording and reading clerks.
Clerks are people who work for the Parliament. Their job is to organise all the business in the Chamber and in Committees, and to make sure that the MSPs follow all the rules.