Within the web development community, a widget is a stand-alone application (self enclosed code) that can be embedded into third party sites by any user on a page where they have rights of authorship (e.g. a webpage, blog, or profile on a social media site). Many websites take advantage of widgets to increase their functionality and customizability.
Types of Widgets
Widgets come in many shapes and sizes, but two of the major types today are Web widgets and Desktop widgets.
Web widgets are intended for use on (embedding in) webpages and have major implications in areas such as site performance, SEO (search engine optimization)and even backlink campaigns.
Example: http://www.finalaya.com/Market_Snapshot_widget.aspx
Desktop widgets are embedded on local computers, and do not impact SEO or webpage performance.
Example: http://www.adityabirlamoney.com/ToolsAndDownloads/Widget.aspx
Financial Widgets
Widgets catering to the requirement of financial community is called financial widget. Please see picture below:

End Use of Widgets
Financial Widgets are typically used to embed with blog, webpage or social networking page to highlight/display relevant information mostly free of cost
Retail users can use widgets for managing their personal finances.
Major Financial Widget Providers
For International Financial Market
• SaneBull
• Yahoo Finance
• Macroaxis
• WidgetBox
For Indian Financial Markets
• Finalaya
References: http://en.wikipedia.org/wiki/Web_widget