Bike categories blur together in marketing, but the actual riding position and tire width are what determine how a bike feels and where it's actually good to ride.
The three basic types
Road bikes put the rider in a lower, more forward-leaning position with drop handlebars, on narrow, high-pressure tires. This position is more aerodynamic and efficient for speed and distance on pavement, at the cost of comfort for casual riders and poor performance off smooth roads.
Mountain bikes put the rider more upright with flat handlebars, on wide, knobby, lower-pressure tires, usually paired with front (and sometimes rear) suspension. Built for stability and control over rough, uneven terrain, at the cost of speed and efficiency on smooth pavement.
Hybrid bikes sit deliberately between the two — a more upright position than a road bike, tires wider than road but narrower than mountain, and usually no or minimal suspension. A reasonable, versatile default for general commuting and casual riding that isn't heavily weighted toward speed or rough terrain specifically.
Frame size matters more than most other specs
A frame that's the wrong size can't be fully corrected with seat and handlebar adjustments — it affects reach, standover height, and overall handling in ways that adjustments alone don't fix. Sizing charts vary between brands even for the same rider height, so it's worth checking a specific brand's own sizing guide, or better, test-riding in person, rather than assuming a size that fit a different brand's bike will fit this one too.
The one thing people forget
Budget for a helmet, lights, and a lock as part of the actual cost of the bike, not as optional extras to add later. A helmet is non-negotiable safety equipment, and lights and a decent lock are what actually make a bike usable and secure for regular transportation use, not just weekend rides.