The term "mounted" can have several different meanings depending on the context in which it is used.
In a general sense, to be mounted means to be placed or positioned on something else, often by being attached or affixed to it. For example, one might say that a picture has been "mounted" onto a wall if it has been hung up using a frame or other method of attachment.
Another possible meaning for the term is when referring to animals, particularly horses. To be "mounted" in this context means to be riding on an animal's back, with one's feet placed in special stirrups that allow them to stay seated while moving. This can also refer to a person or object being carried by the animal, such as a knight on horseback.
In additionally, "mounted" could be used when referring to something that has been recorded or preserved in some way, particularly if it is displayed for others to see. For example, one might say that a painting has been "mounted" onto a wall if it has been framed and hung up.
Overall, the term "mounted" can have several different meanings depending on its context of use, but generally refers to something being placed or attached onto another thing, or being carried by an animal.