Amit Kumar

  A memory is just like a human brain . It is used to store data and instructions. Computer memory is the storage space in the computer , where data is to be processed and instructions required for processing are stored. The memory is divided into a large number of small parts called cells . Each location or cell has a unique address , which varies from zero to memory size minus one. For example, if the computer has 64k words, then this memory unit has 64 * 1024 = 65536 memory locations. The address of these locations varies from 0 to 65535. Memory is primarily of three types − Cache Memory Primary Memory/ Main Memory Secondary Memory Cache Memory Cache memory is a very high-speed semiconductor memory that can speed up the CPU . It acts as a buffer between the CPU and the main memory . It is used to hold those parts of data and program which are most frequently used by the CPU . The parts of data and programs are transferred from the disk to cache memory by the opera

  Data Definition Data Definition defines a particular data with the following characteristics. Atomic  − Definition should define a single concept. Traceable  − Definition should be able to be mapped to some data element. Accurate  − Definition should be unambiguous. Clear and Concise  − Definition should be understandable. Data Object Data Object represents an object having a data. Data Type Data type is a way to classify various types of data such as integer, string , etc. which determines the values that can be used with the corresponding type of data, the type of operations that can be performed on the corresponding type of data. There are two data types − Built-in Data Type Derived Data Type Built-in Data Type Those data types for which a language has built-in support are known as Built-in Data types. For example, most of the languages provide the following built-in data types . Integers Boolean (true, false) Floating (Decimal numbers) Characte r and Strings Derived