China's tank development consisted of three phases. Prior to 1950 China relied on foreign-made tanks purchased from or supplied by France (Renault NC31), Britain (Vickers Mk.E B), and the USA (M5A1 Stuart), as well as tanks seized from Japan at the end of WWII (Chi-Ha). Chinese tanks through Tier IV represent this period. In the early 1950's China was heavily influenced by vehicles of other nations, notably the T-34 and the IS-2, which were provided to China by the Soviets together with design and fabrication assistance for local production. By the late 1950's China began developing its own tanks by making modifications and improvements on the Soviet T-54 design. The Type 59 main battle tank and Type 62 light tank were the first Chinese tanks to be mass produced. The premiums Type 64 and M41D were produced and developed by the ROC from Taiwan, which strongly resemble some USA light tanks characteristics, being somewhat agile with a fast firing gun.
For the most part Chinese tanks have unparalleled mobility, good camouflage values, and sloped armor, making them very flexible regardless of if they're heavy, medium, or light. They still play as you would expect but can often change their combat role a bit when necessary. However, they have very poor gun depression, even worse than German or Soviet tanks, and arguably the worst in the game. They also have very poor module health, and their modules are densely placed, resulting in frequent crew loss, destroyed tracks, fuel tank fires, and ammo racks. However while most Chinese tanks have (comparably) poor hull armor their turret armor is unparalleled, sometimes even surpassing the hull armor values of heavy tanks.
Chinese Light Tanks are fast, agile, and have good penetration and alpha damage. They play very much like medium tanks -- cover fire support and scouting when the team needs it. Their armor -- although (except Tier X) sightly better than foreign counterparts -- is really the only thing identifying them as light tanks. They suffer from poor gun depression and vulnerable modules. The top of the tree; WZ-132-1 is notable for having surprisingly decent protection among the ranks of lights that is comparable to medium tanks.
Chinese Medium Tanks are, up to a point, very similar to the Soviet ones, combining mobility and firepower at the expense of a low rate of fire and poor gun handling. At higher tiers they gain firepower and become more adept at brawling than their Soviet counterparts, while being less well-rounded.
Chinese Heavy Tanks are also similar to the Soviet models on which they were based. These tanks have good frontal armor and acceleration and faster rates of fire, which makes it possible to play them as "heavy" mediums. Later on they focus more on armor sloping and high maneuverability.
Chinese Tank Destroyers are mostly fictional "what-if" vehicle based on existing platforms, denoted by the likely-fictional suffix "FT" (possibly a shorthand for 反坦克/"Fǎn Tǎnkè", or "Anti-Tank"). The line starts out with converted seized/imported tanks at Tiers II-IV with decent sustained damage output and mobility, making them capable supporters and ambushers but lacking armor. At Tiers V-VII are conversions of domestic-made vehicles that all still retain the "glass cannon" trait. At Tiers VIII-X Chinese TD's drastically change by trading off mobility for heavier armament and protection as switching to heavier base models. Top-tier vehicles, the WZ111G FT and WZ113G FT, carry heavy guns comparable to Soviet ones, and very thick frontal armor with high HP pools capable of standing against punches like German Jagdpanzers could. Like most other Chinese vehicles they are generally hampered by below average accuracy and don't snipe so well.