The distribution box serves as the load centre and distributor of electrical power. A distribution box ensures that electrical supply is distributed in the building, also known as a distribution board, panel board, breaker panel, or electric panel. It is the central electrical supply system of any building or property.
In Other words, Solar ACDB is AC Distribution board and Solar DCDB is DC Distribution Boards. Solar ACDB DCDB is LT panels that distribute power from Invertor to Load. Solar AC Distribution Board is the panel used between solar Inverter and Load to provide overload and short circuit protection.

DCDB (Direct Current Distribution Box)

The DCDB (Direct Current Distribution Box) receives the DC power from the solar Panel and directs it to AC inverter through the distribution box.

ACDB ( Alternating Current Distribution Board)

The ACDB (Alternative Current Distribution Box) is a small solar device that is installed between the solar inverter and your home load. An ACDB includes necessary surge protection devices (SPD), AC fuse, and MCB to protect the appliances from any type of electrical damage or high voltages.
It receives the AC power from the solar inverter and directs it to AC loads through the distribution board.