There are many, and some of them may be substituted for a traditional high chair at home, depending upon your space requirements and preferred mode of operations. Briefly: a booster seat fits in an existing chair. For safety, it should be attachable to the host chair in some way. Some high chairs have a detachable seat which can also be used as a booster. a hook-on high chair attaches to and hangs off the table. The various hook-on seats have varying weight restrictions and may not fit on certain kinds of tables. a sling (a general term) fits over the back of some standard chairs to support and contain your baby. Note that this is not, technically, a high chair. It is a means of seating your child in a standard chair for feeding when you are away from home.