Basically it depends on the user who is using the internet.

In today's world living without internet is kind of not possible if you want to stay updated with the time. 

Positive sites :

Think about the live video calling that has been possible for the sake of internet and the people far from their homes are getting connected with each other with a single click.

The life of job worker is not that satisfactory to almost every one of us now for the sake of internet many of us are working from our home with full satisfaction.

there are many more 

but the negative sites which affects quite a lot of people 

Especially teenagers, the addiction of being in the internet and spending their precious time in chatting, watching movies and in many more adult sites   as well and thus they become addicted to it which impacts the real life in a very hard way.

The misuse of the internet, social media which is affecting almost every age generation in current time. Thus reality is loosing its value.

News/rumors  seems to run like wind through internet. be that it may be true or false. Affecting it both the positive and negative way.

Thus there are both the negative ans positive way it totally depends on the user.