Where your guests will sit to eat, are what escort and place cards boil down to. Escort cards typically direct you to which table you will be sitting at. Place cards often are placed at your seat already, indicating where you should sit when you arrive at the table.
Escort cards are useful when serving a buffet or family style dinner, where it doesn’t matter too much who is seated where at the table.
Place cards are helpful when you choose a plated dinner for your guests. Place cards often indicate what time of meat (or not) the guest is having, so the caterer can prepare ahead of time which tables to bring the food to. Place cards are also used to specifically place people in spots, so if you are navigating dynamics between your guests, opting for place cards may be your preferred option.
Generally, escort cards are seen as less formal, and place cards are seen as more formal.
Do you need either? Technically, no, but it’s not recommended. Guests will spread themselves out and this can make the room uneven, with empty seats in places there shouldn’t be.
Pro Tip: If deciding where guests will sit seems too stressful, delegate that task to a close family member or friend who knows the majority of your intended guests!