Having a general understanding of how memory and addressing works, helps you understand pointers in Delphi (and C/C++). Learning assembler also gives you that knowledge, but there are simpler ways to think about it.
A pointer is a memory location that contains the address to the actual data you want.
Think of a street with houses. Make a list of the houses and their addresses. This is a list of pointers. Each pointer in the list leads to the actual house it refers to.
Delphi and C++ Builder optical barcode recognition library for Android utilizing the ZXing library. It supports UPC-A, UPC-E, EAN-8, EAN-13, Code 39, Code 93, Code 128, Codabar, ITF, RSS-14, RSS-Expanded, QR Code, Data Matrix, Aztec and PDF 417 barcodes. Take a look!
Demo shows an Android application using an Android Service to download an image from the Internet. The Android Service works as a background task, even if the main application is not running. When the image file is downloaded to the device, a notification is presented. Handling the notification loads the image previously downloaded. The service stops itself after performing the download process.