The rate a new shift inherits when it is created. Shifts already logged keep the rate that applied to them — edit those in the Shifts table. Leave blank for hours without money.

For a job that pays by the month rather than the hour. Set it and the salary replaces the hourly model: it accrues every month the project is active, worked or not, and each shift shows its share of that month’s pay. Clear it to go back to hourly.