Pensions are accomodations that are usually have fewer services than regular hotels. Physically they can be anything from what we would consider a typical B&B in the USA to a hotel-like structure without all the big hotel services.

Or not. Some pensions have expanded to the point that they really are full service hotels, even though the name still has Pension in it.

Typical services/amenities that a regular hotel will have but most pensions will not have: Meeting/conference rooms; full service restaurant; extended hour room service; a large, ornate lobby; a professional concierge; bellhops; a bar; swimming pool; exercise room.

Pensions vary from basic to luxurious. We often stay in pensions in Europe and B&Bs in the USA as we don't normally use most of the above listed features.