Is Unity 3.4.2 free

I clicked on download and then it showed me a page with a button saying download 3.4.2 and i’m wondering if its pro or free

Every Unity installation contains the whole Unity version. You have to choose a licence. For all Unity versions there is a free and a pro licence. Just download and install it. after the setup is completed you have to register with your email to get a free licence or to buy one of the pro licences.