LDO is a linear regulator. The linear regulator uses a transistor or FET operating in its linear region,

The excess voltage is subtracted from the input voltage to produce a regulated output voltage. Generally speaking, it is a power management IC, which is generally used to convert 12V into 5V, 3.3V,1.8v. We make liquid crystal panels and use them a lot. We use LDO and DC-DC of Shanghai Bellevue. The quality is very good, and there are other manufacturers, such as Wei Meng.