A service menu is the list of what you do and what it costs. In hair, beauty and wellness it usually gives the length of each service as well, because that tells a client how long to allow and tells the diary how long to block. The menu appears on the wall, the website, the booking page and in the head of whoever answers the phone, and it works best when all of those are the same list.
A good menu names services the way clients ask for them, gives one price per line, and splits a service into separate lines rather than printing "from" prices wherever it can. A service that genuinely cannot be priced without seeing the client gets a consultation line of its own.
In practice
A beauty salon's old menu has 46 lines. Eleven carry "from" prices, and 6 are services the owner has not performed in a year. The rewrite removes the 6 dead lines, splits the 11 vague ones into fixed prices by area or by length, and times every line against the real minutes taken. Calls asking what something actually costs drop away, and two facials that had been booked at 45 minutes but took 60 are corrected, which ends a run of late finishes.
Review the menu every quarter, and change it in one place first so that every copy follows. There is a longer guide in how to write a service menu that sells.
In Glow Line
The services on your Receptionist page are your menu: up to thirty, each with a name, a price and minutes. The assistant quotes from that list and nothing else, and the booking page's drop-down uses the same one. See services and hours.