One of the most challenging photos to take is a human portrait. It requires ample knowledge about facial gestures, figures, and the manipulation of light, depth, and even shutter speed. To sum it all up, quality and resolution are your primary concerns when taking a portrait photo.
There are a lot of cameras in the market that can take good pictures of human beings, but it takes additional equipment to get a better output, especially if you are taking a close-up photo or a distant person
Using a Crop sensor or full-frame body
This will help you either get a full body or a close-up photo. Crop sensors are best for headshots while full-frame cameras are best for a whole-body snapshot. Bokeh is also an add-on but not necessary when taking portraits.
One thing you would notice in a studio photography setup is the use of a hot shoe, a handheld or stand-alone flash connected to your camera via a wireless transmitter. Lighting is limited in studios so artificial lights have to mimic natural lights to get a natural look on the subject.
Street or outdoor portraits
You may want to consider having a smaller mirrorless camera (at a minimum) to get the best shots for city portraits, telephotos (added with telephoto lenses), and even casual photographs.