[1] Commonly, it is a virtuosic passage performed as a solo, and often in a cadenza.
The term implies "effect for effect's sake", therefore, while many pieces of Beethoven do require a high skill, they are not described as "bravura".
Fuller-Maitland suggests the following arias as examples of bravura: "Let the bright Seraphim" from Samson, "Der Hölle Rache kocht in meinem Herzen" (Act II of The Magic Flute) and "Non più mesta" from La Cenerentola.
[1] The term "bravura" also refers to daring performance in ballet, e.g., in reference of the pas de deux from Le Corsaire.
[2] Lynn Garafola describes the Russian ballet school of Marius Petipa as "marrying the new Italian bravura technique to its more lyrical French counterpart".