Simple 5G terms definition
Band is a generic term for the proportion of radio frequency. Each 5G operator has one or more frequency bands which are used for radio transmission and reception. Operators typically purchase the right to use frequency bands for their operations from auctions organized by national regulators. In 5G, the low-band refers to spectrum below 1 GHz, mid-band to 1-6 GHz, and high-band to spectrum range above 6 GHz.
Base Station refers to a physical site where radio and transmission equipment are located for interconnecting user equipment (UE) and cellular network. In 5G, the radio component is called gNB (next generation Node B). In LTE, it is eNB (evolved Node B), and in 3G it is NB (Node B).
CA (Carrier Aggregation) refers to the combining of radio capacity of two or more radio frequency bands for a single user. CA has been applied since 2G, but 5G is able to benefit even more from it, thanks to the wider defined bandwidths.
Core Network connects the 5G base stations and delivers the data traffic and signaling between the user equipment and destination such as other mobile user equipment or server. In 5G, the core network is based on virtualized architecture, clouds, and data centers.