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To understand the concept of Planck distribution, we first need to look into the history. Max Planck studied how radiation changes with temperature and came up with a formula to describe this behavior. This formula explains how much energy is emitted at different wavelengths by a blackbody at a given temperature.

The Planck distribution is crucial because it describes the spectral radiance (amount of light energy) emitted at each wavelength of light by a blackbody. It's important to understand that Planck’s formula shows that objects emit radiation continuously across the spectrum, but the intensity varies with wavelength. The peak wavelength can be predicted using Wein's Displacement Law, showing that as the temperature of a body increases, the peak of the emitted radiation moves to shorter wavelengths.

In simple terms, the hotter an object, the more energy it emits and the bluer (or shorter in wavelength) its light becomes. This distribution is verified by observing cosmic background radiation, like the one mentioned in the problem, which shows how energy signatures from the universe's inception confirm the laws of physics.

The electromagnetic spectrum is the range of all types of electromagnetic radiation, from very long radio waves to extremely short gamma rays. Understanding the electromagnetic spectrum is essential in physics as it helps us understand how objects can emit, absorb, and reflect energy.

The spectrum is divided into sections based on wavelengths, with visible light being a small part of it. Other parts include:

• Radio waves: Longest wavelengths, used in broadcasting and communication.
• Microwaves: Following radio waves, used in microwave ovens and some communication technologies.
• Infrared: Used for night-vision equipment and thermal imaging due to its heat emission.
• Visible light: The small range visible to human eyes, between infrared and ultraviolet.
• Ultraviolet, X-rays, and Gamma rays: Shorter wavelengths, useful in medicine, research, and observing distant astronomical objects.

Based on the calculation in the exercise, with a peak at 1062 micrometers, the radiation falls into the microwave region. Microwaves have longer wavelengths than infrared but shorter than radio waves, making them a crucial tool for scientific observation and everyday technology.

Blackbody radiation refers to the type of electromagnetic radiation that is emitted by an idealized non-reflective body, or 'blackbody,' at a specific temperature. Unlike real-world objects, a perfect blackbody absorbs all incident radiation without reflecting any, thereby making it the perfect emitter as well.

Why do physicists care about blackbody radiation? Mainly because it serves as a model to comprehend how real bodies emit radiation. The radiant energy is emitted across a wide range of wavelengths, and the intensity of radiation spans the electromagnetic spectrum, though it is largest at the wavelength determined by the temperature of the body.

It is this quality that allowed scientists to delve deep into understanding cosmic phenomena such as the Big Bang. The cosmic microwave background radiation, being a leftover from the Big Bang, acts very much like blackbody radiation and peaks in the microwave range at a temperature of around 2.7 K. Using the principles of blackbody radiation and Planck distribution, scientists can extract significant information about the early universe and the laws governing the cosmos.