I believe the term used in Church (and commandment) instructions is prohibition of “servile work” on The Sabbath, which is essentially “work for pay.”
(Maybe that’s why I don’t get paid to be an Usher and Eucharistic Minister…

)
There must be some sort of general laxity or dispensation in this area, though… I can’t count the number of times we have gone out to dinner with the priest on Sunday after Mass… surely a priest (and the bishop on at least one occasion) wouldn’t patronize and abet the sinners working at the restaurant, would he?
But, I can remember the days when all the stores were closed on Sundays… the only place in town that was open was the drug store… and maybe the gas station.

Those were much happier days, for sure…