Signal strength describes the level of a received radio signal. It is useful when assessing a wireless link, but it does not capture every factor affecting delivery. Interference, noise, retransmissions, device capabilities and shared capacity also matter, so a strong signal reading is not equivalent to high throughput or an uninterrupted media stream.
A practical example
A television can report strong Wi-Fi while sharing a busy radio environment with many other devices. Moving an access point may change the signal reading, yet reducing interference or improving backhaul may be needed to improve actual sustained delivery.
A common misunderstanding
Do not use a bar display as a complete network diagnosis. Measure relevant performance and compare conditions, because two devices can interpret or display their signal indicators differently.
Related terms
Stable technical definition. Editorial approach