On Mac OS a laptop will suspend to RAM when you shut the lid, when its been asleep for a certain (configurable) amount of time it will hibernate. This is generally good, since you get the fast sleep/wake advantages of suspend and the power saving goodness of hibernate.

Is there any similar thing for Ubuntu?

[I'm currently using Kubuntu 18.04 and loving it, though even suspend doesn't seem to work properly on my XPS 9560, but I guess that's another question]

In Ubuntu 18.04 LTS and above suspend-then-hibernate works similarly

In this mode laptop sleeps or suspends to RAM when the lid is closed of a button is pressed. After a certain time that has been pre-set, the laptop will wake up and write the data in RAM to disk, and enter hibernate mode.

The advantage is, the laptop suspends (sleeps) more quickly when close the lid. If you wake it up before the pre-set time it resumes quickly as well. If you don't wake the it up before the pre-set time it automatically saves battery in hibernate mode shut-down.

In Ubuntu 17.10 and below hybrid-sleep was the closest

In this mode the data in RAM is written to disk for hibernating before the laptop entered sleep (also known as suspend) mode. If the battery gets critically low while sleeping, the laptop goes into hibernation before turning off power, so the data in RAM is not lost.

In case the battery is drained out while the laptop was in hybrid sleep mode, plugging it into the power socket and powering it up will bring it back to the state when the lid was closed to put the laptop to sleep.

See What is hybrid suspend for some more explanations.

From the Ubuntu manpage on systemd power-saving mode:

systemd supports four general power-saving modes:

suspend

    a low-power state where execution of the OS is paused, and complete power loss might

    result in lost data, and which is fast to enter and exit. This corresponds to suspend,

    standby, or freeze states as understood by the kernel.



hibernate

    a low-power state where execution of the OS is paused, and complete power loss does

    not result in lost data, and which might be slow to enter and exit. This corresponds

    to the hibernation as understood by the kernel.



hybrid-sleep

    a low-power state where execution of the OS is paused, which might be slow to enter,

    and on complete power loss does not result in lost data but might be slower to exit in

    that case. This mode is called suspend-to-both by the kernel.



suspend-then-hibernate

    A low power state where the system is initially suspended (the state is stored in

    RAM). If not interrupted within the delay specified by HibernateDelaySec=, the system

    will be woken using an RTC alarm and hibernated (the state is then stored on disk).



Settings in these files determine what strings will be written to /sys/power/disk and

/sys/power/state by systemd-sleep(8) when systemd(1) attempts to suspend or hibernate the

machine.

See this answer if you want to enable either suspend-then-hibernate or hybrid-sleep in your Ubuntu laptop.

Hope this helps.