What two roles does the executive branch play regarding the laws Congress passes?

The President is responsible for implementing and enforcing the laws written by Congress and, to that end, appoints the heads of the Federal agencies, including the Cabinet. And the Vice President is also part of the Executive Branch, ready to assume the Presidency should the need arise.

Explanation:

El Presidente es responsable de implementar y hacer cumplir las leyes redactadas por el Congreso y, con ese fin, designa a los jefes de las agencias federales, incluido el Gabinete. Y el Vicepresidente también forma parte del Poder Ejecutivo, dispuesto a asumir la Presidencia en caso de que surja la necesidad.

the use of email to replace slower surface mail.

i believe it was spain