xorg-x11-drv-synaptics has been the main X.Org touchpad driver for over a decade. Since Fedora 22, it has been superseded by xorg-x11-drv-libinput which aims to provide a better touchpad experience.
Starting with Fedora 26:
a fresh installation of Fedora will install xorg-x11-drv-libinput instead of xorg-x11-drv-synaptics;
an upgrade from an earlier Fedora will install xorg-x11-drv-libinput and remove xorg-x11-drv-synaptics;
users that need the synaptics driver will need to manually install xorg-x11-drv-synaptics-legacy, which will install the synaptics driver and give it precedence over the libinput driver;
removing xorg-x11-drv-synaptics-legacy will remove the synaptics driver and the system will automatically revert to the libinput driver.