Uniforme vs. farda
While both "uniforme" and "farda" translate to "uniform", their usage depends heavily on the region (Brazil vs. Portugal) and the profession. The distinction involves whether the clothing signifies authority, military status, or general employment.
Uniforme
A2In Brazil, uniforme is the universal term used for schools, sports teams, and almost all regular jobs (office, retail, factory). In Portugal, uniforme is generally reserved for school clothing (uniforme escolar), sports kits, or more formal, prestigious attire, rather than everyday work clothes.
As crianças não gostam de usar o uniforme escolar.
(The children do not like wearing the school uniform.)
A empresa exige o uso de uniforme no escritório.
(The company requires the use of a uniform in the office.)
O jogador de futebol esqueceu o uniforme no vestiário.
(The soccer player forgot the uniform in the locker room.)
Farda
B1In Brazil, farda is strictly associated with the military, police, and firefighters; using it for a waiter or a receptionist would sound strange. In Portugal, farda is the common word for almost all work clothing, used effectively for nurses, waiters, supermarket staff, and factory workers, in addition to the military.
O policial limpou a sua farda antes do trabalho.
(The police officer cleaned his uniform before work.)
Em Portugal, os enfermeiros usam uma farda azul ou branca.
(In Portugal, nurses wear a blue or white uniform.)
O general vestiu a farda de gala para a cerimônia.
(The general put on the dress uniform for the ceremony.)
A empregada de mesa manchou a farda com vinho.
(The waitress stained her uniform with wine.)
Summary
Use uniforme in Brazil for everything except military/police contexts. In Portugal, use farda for most jobs (waiters, nurses, mechanics) and military personnel, reserving uniforme mostly for students and athletes. In Brazil, farda implies authority and weapons; in Portugal, farda simply implies work duties.