An internal iterator is implemented with member functions of the class that has items to step through. An external iterator is implemented as a separate class that can be “attach” to the object that has items to step through. An external iterator has the advantage that many difference iterators can be active simultaneously on the same object.
The ErrorProvider control is used to indicate invalid data on a data entry form. Using this control, you can attach error messages that display next to the control when the data is invalid, as seen in the following image. A red circle with an exclamation point blinks, and when the user mouses over the icon, the error message is displayed as a tooltip.
A DLL (Dynamic Link Library) is a file that can be loaded and executed by programs dynamically. Basically it’s an external code repository for programs. Since usually several different programs reuse the same DLL instead of having that code in their own file, this dramatically reduces required storage space. A synonym for a DLL would be library.
Secure Sockets Layer (SSL) and Transport Layer Security (TLS), its successor, are cryptographic protocols which provide secure communications on the Internet. There are slight differences between SSL 3.0 and TLS 1.0, but the protocol remains substantially the same. The term “SSL” as used here applies to both protocols unless clarified by context.
DLL hell means deploying the same DLL in your application multiple times.DLL Hell can be overcome by versioning, i e; suppose u install some DLL for the first time, it will be V1.0, again if u install the same , this time it will be V2.0, we can differentiate the DLL by its version and depending on our requirement, we can load the respective DLL into our application.