Streaming services like Netflix will adjust to the device you’re using and eat up whatever bandwidth is available to bring you the best quality video possible. So if you’re experiencing Internet issues while streaming, you may want to try going into the app’s data usage settings and adjusting them as necessary. (Netflix, for instance, gives you the options of low, medium, high, and auto [which automatically adjusts the quality based on your Internet connection]. These options allow you to control how much bandwidth the service will use.)
If you find that you’re having trouble using any other device while someone else in your house is streaming on Netflix, visit https://help.netflix.com/en/node/87 to find out how you can adjust your Netflix settings in a way that best fits your household.