There are two main types of CCTV drain surveys:

1. Push rod surveys: This method involves inserting a camera attached to a push rod into the drain. The push rod is then manually pushed through the drain to capture images and footage of the inside of the pipe. This method is typically used for smaller drains and pipes.
2. Crawling robot surveys: This method involves using a small robot with a camera attached to it to crawl through the drain. The robot is controlled remotely by an operator who views the footage captured by the camera. This method is typically used for larger drains and pipes, and allows for more detailed inspections of the inside of the pipe.

Both types of surveys are used to identify issues such as blockages, cracks, corrosion, and other types of damage to the drain or pipe. The results of the survey can be used to create a report outlining any issues found and recommending appropriate solutions.