A central securities depository (CSD) is a specialist financial organization holding securities such as shares either in certificated or uncertificated (dematerialized) form so that ownership can be easily transferred through a book entry rather than the transfer of physical certificates. This allows brokers and financial companies to hold their securities at one location where they can be available for clearing and settlement. This is usually done electronically making it much faster and easier than was traditionally the case where physical certificates had to be exchanged after a trade had been completed.