Yes, the items are refurbished or used. This doesn't mean they are all in good condition for use. For items like bikes, have all chains been replaced and have all mechanics been fully tested? For tents, have all the upholstery patches been cleaned, tears been repaired and other damage been fixed? If buying fishing rods, have the rod and reel been replaced with new parts and is everything functioning as it should?
Even if an item isn't new, it doesn't mean you can't get quite a bit of use out of it. But, when buying second hand or used, make sure you read all descriptions and find out that everything is functioning as it should and is going to operate safely.
When buying used you always run the risk of dishonest sellers online, trying to pass off knock off items as brand new or genuine when this isn't always the case. For this reason, you have to buy from a trusted merchant. There are companies which specialise in the sale of outdoor and leisure equipment online. Not only do they guarantee the authenticity of items but also their safety, operational condition and most will warrant your purchases as well.
Buying online is a great way to save. Buying pre-owned or refurbished items is an even better way to save. If you decide to do this make sure you consider these important factors prior to buying. Especially with equipment you will be using regularly. You want to know it will last for quite some time and operate as it should regardless of the outdoor activities you enjoy engaging in.