The Tenno are not only masters of gun and sword, but also master craftsmen.
Within the foundry, a Tenno can make their weapons and Warframes at the cost of credits and resources. Buy or farm from the bosses the blueprint of your chosen weapon, have the required resources(which drop specific planets, by killing enemies or destroying containers), and after 12 or 24 hours, your desired weapon is done and ready to be used.
Warframes, however, are special - one must obtain three different blueprint parts(Systems, Chassis and Helmet) from bosses, or special missions, and craft them individually; each part takes 12 hours to complete. Afterwards, buy the blueprint for the Warframe itself from the Market; crafting it requires 3 days.
