Till or glacial till is unsorted glacial sediment.
Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as matrix support, is diagnostic of till.
Glacial till with tufts of grass
Till after avalanche, Norway
Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand and silt can be carried in suspension in river water and on reaching the sea bed deposited by sedimentation; if buried, they may eventually become sandstone and siltstone through lithification.
River discharging sediment into the ocean
Sediment in the Gulf of Mexico
Sediment off the Yucatán Peninsula
Sediment builds up on human-made breakwaters because they reduce the speed of water flow, so the stream cannot carry as much sediment load.