1. Software whose source code is not publicly available and is proprietary, restricting users from viewing, modifying, or distributing the code
Microsoft Windows is a closed-source software that users cannot modify.
Microsoft Windows é um software fechado que os usuários não podem modificar.
2. Proprietary software with restricted access and control over distribution and use
Many companies prefer closed-source software for security reasons.
Muitas empresas preferem software fechado por razões de segurança.