This value indicates how much you trust the owner of this key to correctly verify the identity of the keys he signs. Taking the owner trust into account gpg creates your own web of trust. You trust the keys you signed. If you assign owner trust to these persons you will also trust the keys they have signed without the need that you first have to sign their keys too.
Este valor indica canto se confía no dono desta chave para que verifiquecorrectamente a identidade das chaves que el/ a asina. Ao ter a confianza do dono en conta, o gpg crea a sua propia rede de confianza. O usuario confía nas chaves que asinou. Se lle atribúe a confianza no dono a esas pessoas, confiará tamén nas chaves que asinen, sen ter necesidade de asinar tamén as chaves deles.