This is a basic transport layer that allows for information to be shared. (pcgamesinsider.biz)
For the transport of secure information, usually during the upload / download processes, many sites simply use Transport Layer Security or its predecessor, Secure Sockets Layer, to protect data from being compromised by outsiders while in transit. (realtormag.realtor.org)
The typical design of a perovskite solar cell sandwiches the perovskite between a hole transport material, a thin film of an organic molecule called spiro - OMeTAD that's doped with lithium ions and an electron transport layer made of titanium dioxide, or TiO2. (technologyalpha.net)