There are many dangers online you could get followed by a stranger online as well as that,There are many people online that would want to know your personal information also people online could be able to blackmail you with your personal pictures etc. Always be safe online.
Social Media is were you can contact your friends or other people around the world the are many ways to keep contact with people here are some social medias Facebook ,Instagram
Cyber Bullying is were you get bullied online or on any social medias also there are many strangers around the world that will find a way to bully you online.
How to prevent it
There are many way to stop cyber bulling there would be a button on social medias that says Report Abuse and something would be done about it.Or you could contact child line and talk to them about it.Also you could either screenshot the messages they sent to you and show your parents.
Child line 0800 1111
Make sure not to give anyone online your personal information your password address etc Because anyone can follow you or do something with the personal information you gave them only keep your personal information to yourself
changes of technology
The things that changed in technology is that it has become more safe because you are able to put your account on private and it doesn't show your password as well as that it has a button that you can access if you are getting bullied online