This tool is a drawing tool tailored for generation of schematic diagrams.  These are diagrams that describe the routing of connections (or wires) between electronic components  - see Figure 1.  The diagram shows components drawn in black and wires drawn in blue. 

Of course any painting program could be used to draw exactly the same schematic but this tool adds information to each object.  For example; in order for the tool to identify component pins, pin data is stored within the schematic data base.  This is later used to check that all the pins are connected correctly (i.e. flagging up error warnings if any pins are left unconnected by accident). 

In addition the objects that make up a symbol are grouped together so that when editing the schematic one mouse click picks up the symbol and all the objects (belonging to a symbol) can be moved around as a single item.  User data can also be added to any library symbol e.g. to associate a specific manufacturer with a part.  This can then be output via the bill of materials (a parts list).

Dictionary definition of a schematic :

      schematic 1. a of a schema or scheme; representing objects by symbols 2. n. schematic diagram (concise oxford dictionary).

A schematic is a diagram showing how electronic components are connected together.

In this tool the schematic diagram (or schematic) represents an electronic circuit having symbols and lines representing real world objects (electronic components and pcb tracks).  Examples of components and their schematic symbol are shown below:

Transistor

Although a general purpose drawing program can be used to draw a schematic it will lack features specific to drawing schematics.  Some of the facilities this tool provides are:

• A symbol library for repeatedly pasting copies of parts.
• A part database.  Data held in the database is referred to as attributes.
• Symbol pins.      These allow the tool to identify connections between symbols.
• Wire and line dragging and merging.
• Automatic connection drawing.
• Generating a Netlisting (the schematic is also checked for errors).
• Generating a Bill of Materials (a list of components and quantities of components)

Note that with a simple drawing program each symbol would have to be drawn from scratch whereas the schematic tool provides these symbols from the library.  In addition  the symbol identifiers R1,R2,TR1 etc. are added automatically.  The tool remembers parts that have been added and automatically adds the next one. 

There are three major outputs from this tool

• The schematic page
• The netlist
• The bill of materials

For examples of the other outputs see tool capabilities