A wave can have two types of end points. A fixed end and a free end.
Fixed
Ends will reflect and invert the wave.
Free
ends will reflect but not invert the wave.
*simulation*
An object or system will resonate if it’s driven to its natural frequency. This is like playing a guitar, the string will resonate to produce the note you want to play. Trumpets do not have strings that resonate but air that resonates to produce notes.
The
superposition of reflections and travelling waves on a string can cause
resonance
Resonance
greatly increases the magnitude of oscillation in an object or system.