Malt provides beer with "body". In unison with the hops, it is also fundamental for the taste of the brew.
Depending on the type of malt, it can provide exciting flavors and aromas that complement the aroma of the hops, rounding out the perfect beer flavor. More importantly, malt is the source of the sugars needed for the fermentation.
Malt consists of germinated cereal grains that have been ‘malted’: soaked in water, the grains germinate until, at a very specific point, they are dried with hot air and the germination is stopped.