This is the Name of the security in question. It is likely to be a company name, ETF, bond or index name. Please note that several securities may share the same name if there are more than one class of share.
For Shares this refers to the company name, and will not contain further information on the share class. For ETFs, Bonds and other collective securities there will be more security specific information available in the name such as the Yield and Maturity.