Thanks for your question it’s a really common doubt. Here’s the basic difference:

Polytechnic College offers diploma courses after Class 10 or 12 in technical subjects like mechanical, electrical, civil, etc.

Where as Engineering College provides full B.Tech/B.E. degrees, usually after clearing entrance exams like JEE, CET, or state-level tests.

Polytechnic courses are generally 3 years long and are more practical in nature. After completing a diploma, many students also go for lateral entry into B.Tech in the second year, which is a nice shortcut into engineering with solid fundamentals.

Hope this clears things up for you!