How will I connect two laptops to the internet without using a router?

How will I connect two laptops to the internet without using a router?

The first laptop is connected to the internet through a modem using Ethernet cable..so cross connection isn’t possible but someone told me about ad hoc..but he didn’t teach how to configure it..will anyone teach me to configure the two laptops so both could connect to the internet at the same time..Thanks a lot!