Understanding the fundamental concepts, operating characteristics, and terminology relating to your home telephone will enable you to obtain the most from it. Learning how a telephone system works is the best place to begin. 
The Pair
A telephone system uses only two wires, known as a pair, to place and receive calls. Ninety percent of the working operation of your telephone system deals with the pair and the connecting points where the wires travel to place and receive calls.
The telephone system is almost no more complicated than a child's tin can and string telephone.
To understand the actual working operation of your telephone system, you will need to know how the pair connects your telephone with another.
Telephone Cables
Telephone cables are pairs that are bound together; each telephone's pair is connected with other pairs through a cable network.
In order to keep track of each individual pair, the telephone company uses a standard color code for labeling. This method enables the company to assign and locate a pair at any point within the telephone cable network.
Basically, all telephone cables are alike even though their names vary according to their location. For example, cables placed on telephone poles are referred to as aerial telephone cables; cables placed underfround are called buried telephone cables; and cables that span between the central office and your home telephone are known as local-network telephone cable.
The Local Network
Each telephone system is a part of a local network. The local network consists of a permanent structure of telephone cables, switching equipment, and terminals that provide the fundamental link between your telephone and all others.
The quality of your telephone service is greatly affected by the quality of the local network operation.
The Central Office
The central office (C.O.) is at one end of the local network while your home telephone is at the other end.
As the originating location and nucleus of your telephone system, the central office is the most complex area of the local network, yet all the home telephone user really needs to know about the central office is what functions is provides to the telephone system.
Typical central office. Switching equipment at the central office directs your calk to their desired locations. Other equipment supplies the dial tone, the busy signal and the electrical current necessary for voice transmission. The ringing generator supplies the ring. Some service options depend on what types of supplemental equipment is installed at the central office.
The Cables
The telephone cable that connects one central office with another in a different local network is called trunk cable. 
Two or more cables often have to be spliced in order to increase a cable's length, change its direction, add a service or cross-connect terminal, or repair damage.
Service Terminals
The service terminal, located close to your home, is the final connecting point between the central office and your telephone. There are two types of service terminals; the type you have will depend on the type of home you live in.
The protected service terminal is found at multiunit buildings, structures in which individual units share walls, ceilings, and floors with other units (e.g., apartments, townhouses, and condominiums). This type of service terminal protects your telephone system against high voltages by providing fuses and a ground to earth for each pair connected to it.
The unprotected service terminal is found at single-unit buildings, structures that are independent of others. The unprotected service terminal is used in conjunction with a house protector, which provides the necessary protection against high voltages.
Station Wiring
Your home telephone is linked to the local network through station wiring, which comprises all the wires and connections in and around your home that link your telephone with the service terminal.
The arrangements for station wiring depends on what type of home you live in. Station wiring for single-unit homes includes the drop wire, house protector, inside wire, and phone modular connectors (PMCs). For multiunit buildings, the station wiring includes only the inside wires and the PMCs. 
The House Protector
The house protector is attached to the outside of your house, serving to protect it, your telephone, and you against high voltages. Fitted with fuses and an earth ground, just as is the protected service terminal, the house protector provides a location where all the inside wires can be attached.
Inside Wire
The inside wire, which connects the house protector or protected service terminal to the phone jack inside your home.
The Phone Jack-Phone Modular Connector
The phone jack, the point where you plug your telephone into the telephone system, is a terminal at which the inside wire is connected.
Telephone Instrument
Buying Guideline
With such a wide variety of telephone instruments available on the market today, choosing the one that best suits your needs can be difficult. In addition to price, you need to consider a telephone's components, construction, and accessories. And always keep in mind the desired end result—communication. If a phone's sound quality is poor or static interferes with important calls, you won't be satisfied, even if you did save a few dollars.
The telephones of the Company TELCO are perfect technically, guaranteed one year in every part of his. Also being technically to the vanguard hey have produced of tall craftsmanship, destined to last in the time. They can be left in inheritance. They can become objects of antiques and our telephones of 30 years ago they are it, many shops of antiques expose our rotary telephones.
Therefore our telephones are an investment that lasts in the time.
Basic Components of a Telephone Instrument
This chapter begins by exploring the basic components of conventional telephone instruments (as opposed to the more contemporary instruments that are molded shut and therefore nonenterable, making component repair and replacement impossible).
The handset cord, consisting of four wires that connect the transmitter and receiver to the network, is usually the first component that will need replacing. On frequently used telephones, the cord often becomes stretched out, kinked, or even broken.
To replace the transmitter or receiver, simply unscrew the coverplate.
To examine the internal components of your telephone instrument, you must first be able to get inside. For the desk and wall telephone, simply turn the instrument over. Unscrew the screws that hold the cover on and then pull it off.
Once the telephone instrument is open, the internal components will be exposed and shows the inner workings.
The network is that point where line cords and handset cords connect. The easiest method for replacing these cords is to handle only one wire at a time: simply remove one wire from the old and replace it with the new.
If a telephone instrument is dropped hard, often the return spring attached to the hook switch will fall out of place and you will not be able to get a dial tone because the hook switch will not make proper contact. To repair this, simply open up the telephone instrument and reset the return spring .
Telephone instrument ringers are rated in a standard ringing power unit called the Ringer Equivalence Number (REN); every telephone should have an REN stamped on it. Telephone companies generally supply an REN of five to your home, so if your telephone instruments' RENs total more than five, your instruments' ringers may not work.
It is important for a telephone instrument to stay dry and clean. 
To every way, all the parts of our telephones are well described in "Spare Parts"