I believe those web sites also incldue condos - you can select the property types when doing your search.
Owning a condo, you have to pay condo fee (a few hundred $ per month) to cover common maintenance and repairs as well as salary for building manager or superintendent, and you are bound to the condo specific agreement. Most cases (with well-built and well-managed condos), you are ok. But some condo buildings, especially old ones, may require that the unit owners make significant amount (in thousands) of special charges/contribution (in addition to normal condo fee) every year or a few years to make the building safe you definitely want to avoid involving such buildings.
Owning a house or a freehold townhouse, you decide what and when to do maintenance and repairs, and you decide how much to spend for that and hiring someone ot DIY.