There are 18 groups (columns) in the periodic table. Group 1 (also known as the alkali metals) is the column on the far left of the table. Elements in the same group have similar, but not identical characteristics. This is because they all have the same number of electrons in their outermost shell.
Software. Sometimes abbreviated as SW and S/W, software is a collection of instructions that enable the user to interact with a computer, its hardware, or perform tasks.
A computer is an electronic device that processes data by following a set of instructions. A computer system is a set of parts, including the computer itself, that work together to perform tasks. These tasks may be relatively simple, as in a calculator, or they may be very complex, as in air traffic control systems.