The farther away from the router you are, the lower your signal strength. Moving your router around in the room or moving it to another room can sometimes make a noticeable difference. Generally, the best location for your router is as close to the middle of your home as possible or the second floor for a two-story house.
It's best to keep it off the floor and away from walls and large metal objects like filing cabinets. Avoid placing it next to windows, closets, or behind something that might weaken its signal, including TVs, aquariums, kitchen appliances, etc.