In debug compilation, assert takes in a Boolean condition as a parameter, and shows the error dialog if the condition is false.  The program proceeds without any interruption if the condition is true.

A SAX parser warning is generated when the document's DTD contains duplicate definitions and in similar situations that are not necessarily an error but which the document author might like to know about, because they could be.

If an assembly is installed into the BIN directory, the code must be ensured that provides error
handling in the event that required permissions are not available. Otherwise, unhandled security
exceptions may cause the Web Part to fail and may affect page rendering on the page where the
Web Part appears.

A runtime  error.

An event-driven interface in which the parser invokes one of several methods supplied by the caller when a parsing event occurs. Events include recognizing an XML tag, finding an error, encountering a reference to an external entity, or processing a DTD specification.

PL/SQL exception handling is a mechanism for dealing with run-time errors encountered during procedure execution. Use of this mechanism enables execution to continue if the error is not severe enough to cause procedure termination.

The exception handler must be defined within a subprogram specification. Errors cause the program to raise an exception with a transfer of control to the exception-handler block. After the exception handler executes, control returns to the block in which the handler was defined. If there are no more executable statements in the block, control returns to the caller.