When the input is white light from an incandescent bulb, the output is a few discrete lines. The pattern of the wavelengths of these lines is unique to hydrogen.

The atomic emission spectrum is the pattern formed when light emitted by an element is separated into the different wavelengths it contains.

the model that explains atomic emission spectra is called Bohrs' Model

When the input is light from a hydrogen lamp, the output from the spectroscope is a continuous spectrum of all colours and visible wavelengths.

Different wavelengths, or distances between crests of waves, of light result in different colours of light.

Each element emits specific colors of light that correspond to specific wavelengths.

two or more elements can have the same atomic emission spectra