A pointer is a reference to a memory address.

A reference type is known by a reference to a memory location on the heap.A value type is directly stored in a memory location on the stack. A reference type is essentially a pointer, dereferencing the pointer takes more time than directly accessing the direct memory location of a value type.

A delegate in C# is like a function pointer in C or C++. A delegate is a variable that calls a method indirectly, without knowing its name. Delegates can point to static or/and member functions. It is also possible to use a multicast delegate to point to multiple functions.

It is a useful, memory-saving technique for multiprogrammed timesharing systems. A Reentrant Procedure is one in which multiple users can share a single copy of a program during the same period. Reentrancy has 2 key aspects: The program code cannot modify itself, and the local data for each user process must be stored separately. Thus, the permanent part is the code, and the temporary part is the pointer back to the calling program and local variables used by that program. Each execution instance is called activation. It executes the code in the permanent part, but has its own copy of local variables/parameters. The temporary part associated with each activation is the activation record. Generally, the activation record is kept on the stack.

mysql_fetch_array - Fetch a result row as an associative array and a numeric array.
mysql_fetch_object - Returns an object with properties that correspond to the fetched row and moves the internal data pointer ahead. Returns an object with properties that correspond to the fetched row, or FALSE if there are no more rows
mysql_fetch_row() - Fetches one row of data from the result associated with the specified result identifier. The row is returned as an array. Each result column is stored in an array offset, starting at offset 0.

Object Linking and Embedding (OLE) clipboard is a more capable clipboard than the windows traditional clipboard. To transfer a large image using a legacy clipboard one must allocate enough memory space to copy this image. However using the OLE clipboard you can transfer the bitmap in a more sensible medium like a file on a hard disk.OLE drag and drop is a visual method of transferring data. Unlike having separate commands like cut, copy and paste the OLE drag and drop lets you grab a piece of data with the mouse and drop it in the desired location.So to summarize it there are two broad differences between OLE and legacy clipboard. OLE clipboard is completely COM based and secondly it supports storage medium other than global memory.OLE drag and drop is programmatically very similar to OLE clipboard. The data provider or data source creates a data object that encapsulates the data and makes an IDataObject pointer available. The data consumer or drop target retrieves the IDataObject and uses it to extract data from the data object. The drop source initiates a drag and drop operation by passing an IDataObject pointer to ::DoDragDrop. Any window that is interested inbeing a drop target registers itself with the system by calling ::RegisterDragDrop. If drop occurs in a registered window then the drop target is handed the IDataObject pointer passed to ::DoDragDrop.