in carboxylic acid: Hydroxy and keto acids. ...not the same. The 2-hydroxy acids form cyclic dimeric esters (formed by the esterification of two molecules of the acid) called lactides, whereas the 3- and 4-hydroxy acids undergo intramolecular esterification to give cyclic esters called lactones.
VBA's ActiveWorkbook property refers to the workbook with the focus. The active workbook may or may not contain the code that's referencing the active workbook, which is an important distinction. It's perfectly acceptable to use this property to reference the active workbook from code inside the active workbook.
So what exactly is an Ultrabook and how is it different than a laptop/tablet/PC? The definition of an Ultrabook is a high-end subnotebook defined by Intel. Ultrabooks are designed to be light weight without compromising performance and battery life. They use low-power Intel processors with integrated graphics and unibody chassis to fit larger batteries into smaller cases.