FCL or Full Container Load is a standard set by the ISO (International Organisation for Standardisation) which refers to one 20 or 40ft container filled with cargo. A shipper uses up the space of the entire container.
LCL or Less than Container Load refers to a shipment that doesn't fill one 20 or 40ft standard container. In the case of LCL, several shippers load their cargo into a single container. While LCL is the cheaper option for small shipments, it costs more money per unit of freight as compared to FCL.