Your question is a bit like asking "how long is a bit of string?", but in general terms freight is moved in 'block' train-loads from one point to another. These traffic flows include:
Container traffic between ports and road distribution depots; Oil and oil-based fuels between ports, refineries, power plants, distribution centres; Coal from Collieries and ports to power plants.
Other traffics include steel and other metals; chemicals; cars and other vehicles; Cement, bricks, precast concrete panels etc. for building; and of course spent nuclear fuel from power plants to the recycling and processing plant at Sellafield.
I am sure that this list is not inclusive.
Retired UK Train Driver, lifetime of interest