|“||The difference between men and boys is the price of their toys||”|
|— A common axiom|
At its most simplest a toy is an object used in play. A toy can be an item explicitly manufactured to be used in play (such as a rocking horse) or just an everyday object co-opted into play (like a blanket)
Toys have a strong association with children and pets, for they are often seen not need a reason to simply play hence are expected to have items that serve no purpose other than to help play. Adults will feel they need an excuse to own such an item. A bicycle goes from something that simply fun to ride, to exercise equipment.