Why is there only one core in my task manager performance graph?

Question

I have a new laptop and I checked how many CPU Cores I had via the Device Manager, as can be seen here:

But when I looked at Task Manager I saw only one graph of one Core only, on the performance tab. Is my computer only using one core? Why?

System Settings:

OS: Windows 10 64bit Lenovo laptop, 8GB RAM, CPU(Processor): Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz 1.80GHz

Solution

Windows 10 by default shows overall utilisation instead of per core utilisation. In most cases, and for most users I assume it's more useful

Simply right-click on the graph and you can change the views.