What kind of law/case is it when a company has very similar packaging and product names to a competitor?

Question

For example, there's a product on the market and a competitor makes a similar product with very similar packaging. If the first company wanted to take legal action, on what formal legal grounds would they pursue this case?

Answer 1

Trademark Infringement

Answer 2

COMPANIES IN THE UNITED STATES ARE FULLY PROTECTED AGAINST IMITATION BY ALL FEDERAL COURTS.IN THE THIRD WOLD COUNTRIES,YOU CAN COPY AND MARKET MOST THINGS.