The degree Kelvin (K) is the unit used to classify the color temperature according to the scale created by William Thomsom from degrees Celsius. Lord Kelvin based on the table of William constructed a scale of temperatures to which its name is attributed to him.
A deeper explanation would introduce us into the world of physics, so in our sector knowing the relationship between Kelvins and kind of light will be sufficient.and.
This measurement factor is useful to know at a glance which tone or quality of light has a certain light source, for example, if we are going to buy a light bulb or a fluorescent we may be interested in knowing the kelvin it provides, as it will depend on This factor whether the light will be yellow or white.
The lower the kelvin value will be the light temperature, for example a 1600K bulb will have a temperatUra and color quality similar to the light of an exit or sunset. While a light bulb with 5000K will be more like daylight.
To better understand the relationship between kelvin and light temperature is attached the following table, where in a visual way it becomes easier to choose the type of bulb that best suits our needs.

A: It is equivalent to the temperature of a candle, it is aIn yellow light.

B: It resembles the color of dawn, it is similar to a tungsten bulb.

C: It is the tone of light of the old bulbs that were not led, filament bulb.

D: Similar to a study light.

E: Similar to mid-afternoon light about 20 °, similar to a fluorescent light warm.

F: Similar to mid-afternoon light at about 30 °.

G: Daylight, similar to a lightOf a flash.

H: Sunlight at noon.

I: Very sunny day and clear sky.

J: Partly cloudy day.

K: Cloudy day.

L: Wide shade clear day.

M: Very cloudy day.

N: Blue sky without sun.

O: Very clear day.

The socket is the part that allows connecting the bulb to the socket. There is a wide selection of bushings for different types of bulbs. The nomenclature for each type includes 1 or more letters (type of lampholder), followed by 1 or more numbers (diameter of lampholder).
Example: The bush E27 would correspond to the type of thread E (Edison) of 27mm in diameter.

• E12: Diameter of 12mm, this is a tamYear smaller than the most commonly used standard E27.
• E14: It is the second most common cap, only varies a little of the E27, with a diameter of 14 to 17 mm. It is normally used for bulbs or lamps.
• E27: This is the most common cap. It has a thick cup shape with thread to be able to adapt to the connector. It measures 27mm wide.
• E40: Has a diameter of 40 mm, it is the largest thread of this tIpo.
• G4: With a distance between pins of 4.0 mm. It is a type of cap that is frequently used in appliqués, ceiling lamps and hanging lamps.
• G5.3: With a distance between pins of 5.33 mm. The GU 5.3 socket format is a format widely used in small led floodlights with transformer. Usually used in halogen lamps and dichroic halogens.
• GY6.35: With a distance between pins of 6.35 mm, trOf a model similar to the previous one.
• G9: With a ditancia between pins of 9,0 mm. Usually used for ceiling lamps and hanging lamps.
• G13: With a distance between pins of 12,7 mm. It is used in fluorescent tubes.
• GX53: With distance between pins of 53 mm. Its most common use is the installation in light bulbs to illuminate furniture or unusual places. It does not need transformer.
• GU10: With a distance between10 mm pins. The GU10 bushing shape is a widely used format in small transformerless LED spotlights. Usually used in dichroic halogen lamps.
• B22: Type of bayonet connector used in countries such as Africa, India and Ireland.
• MR16: Its use is normally limited to 12V halogen lamps.

VAC would be the abbreviation of Volt Altern Current which would be translated Volts of alternating current. The difference between VDC is that its sinusoidal oscillation achieving a more efficient energy transmission.

The alternating current is the energy that we receive in our homes, it is generated in the power plants by means of alternators.

The intensity of this type of current varies with time, and changes direction 50 times throughsecond (50hz). The generated voltage changes in the form of sine wave so it is not constant.

In the image:

1. Current by pulsations.
2. Direct current (DC).
3. Alternating current (AC).
4. Variable current.