My phone keeps crashing and restarting on its own. What can I do to stop this from happening? Is there a certain reason it happens?

This can be explained in easy steps.

For Android Phone Users.

We use to install end number of applications and put lot of data in our mobile phones.

As we know there is a limited storage and RAM in side , capable to run limited apps at a time.How ever there are several upgraded mobiles as well having good RAM and memory as well still these devices hang and crashes at times.

So the best way to get rid of these issues are :

We should keep only necessary application which we use in our day to day life, rest we can keep disabled or install a the time of need.

We should always install apps from play store not by receiving from third party apps and install.

If a particular application is crashing continuously , we have to check for updates , we can reinstall else clear data or cache memory , but before doing that we have to take the save the incomplete data.  

Max we can do factory reset.

first of all back up your data,you then do factory rest if the problem persist.you reload the operating system or you do software update

Doing a software update or reloading the software would resolve the issue,you can also do a factory reset but be aware that you need to back up your data before you do the reset because you will lose all data on the device