A Leased Line is a dedicated connection between the local exchange and your premises.  Leased Line Service is fixed bandwidth which has equal speeds of upload and downloads which is not open to conflict with other users.

A leased line is a network link that links two sites, rented from a service provider. These are also the premises of a company and the data center of a network operator. Speeds can range from 2Mbps to 10Gbps (megabit per second) (gigabit per second). While historically supported by a fiber optical cable, this is evolving with Ethernet in the First Mile (EFM), with either Layer 2 or Layer 3 protocols. There would be no disagreement over a decent leased line operation, which suggests it is not shared with anybody else.

Broadband is not a dedicated link between the local exchange and your premises. It is variable latency, asymmetric, which means quicker than uploads for updates, and open to dispute with other users.

A fiber broadband link is a link between two points, typically a company premise and a data center or network node again.
It isn’t very true to compare these two providers. There are very different goals of both programs. A Leased Line could be for you if you have a bigger number of customers, or if your company losses income if it loses the link.

What else you can do with a Leased Line is another thing to remember, to improve its usefulness. We also have bandwidth-segmented leased lines to operate other programs that do not require access to the internet. Two examples are remote real time backup and SIP trunks. The leased line then makes the company work better and offers internet service with high bandwidth.