Newborns sleep, a lot. They sleep to give their brains and bodies time for development. Newborns have a unique sleep cycle compared to adults. Unlike adults, newborns only have 2 phases of sleep: quiet sleep and active sleep. Quiet sleep is similar to NREM3 sleep while active sleep is like REM in adults. Newborns sleep around 8 hours in total during the day and 8-9 hours at night totaling 16-18 hours of sleep during a 24-hour cycle.
At this point, your baby's sleep phases are the same as yours. This is not too significant but is just something that you should note. As it has been said many times, sleep is vital for development. At this age, as they are phasing out of sleeping more than they are awake, it is important to make sure there is some kind of variation between naps and sleeping at night.
A lot happens during the toddler stage. Milestone after milesotne is being achieved. This is also a sign that there is a lot of cognitive development. A common milestone for this age is reducing nap time and some even completely eliminate it. No matter what you decide is best for your child, make sure they are still getting enough sleep. If they drop nap time, they might need to have an earlier bedtime to compensate for the lost sleep time.