In conventional usage, boredom is an emotional and occasionally psychological state experienced when an individual is left without anything in particular to do, is not interested in their surroundings, or feels that a day or period is dull or tedious. It is also understood by scholars as a modern phenomenon which has a cultural dimension. "There is no universally accepted definition of boredom. But whatever it is, researchers argue, it is not simply another name for depression or apathy. It seems to be a specific mental state that people find unpleasant—a lack of stimulation that leaves them craving relief, with a host of behavioural, medical and social consequences."[1] According to BBC News, boredom "...can be a dangerous and disruptive state of mind that damages your health"; yet research "...suggest[s] that without boredom we couldn't achieve our creative feats."[2]

The most common way to define boredom in Western culture is having nothing to do. Boredom is generally viewed as an unpleasant emotional state in which the individual feels a pervasive lack of interest in and difficulty concentrating on the current activity. The condition corresponds more precisely to the French ennui, an existential perception of life’s futility. Ennui is a consequence of unfulfilled aspirations (Goodstein, 2005).
Boredom also has its benefits. It is important to see boredom as a “call to action” (Svendsen, 1999). Nietzsche suggested that men of rare sensibility value boredom as an impetus to achievement. Boredom can be a catalyst for action. It can provide an opportunity for thought and reflection. It can also be a sign that a task is a waste of time—and thus not worth continuing.
Finally, a real problem caused by boredom is that it leads you to dislike the things that are the object of boredom. In my senior year of high school, for example, I was forced to read Moby Dick. I struggled to get interested in it and spent long hours staring at the pages trying to lose myself in it. To this day, I really do not like Moby Dick. The negative feelings that came with the boredom have stuck to the book.

Lethargy is a state of tiredness, weariness, fatigue, or lack of energy. It can be accompanied by depression, decreased motivation, or apathy. Lethargy can be a normal response to boredom, inadequate sleep, overexertion, overworking, stress, lack of exercise, or a symptom of a disorder. When part of a normal response, lethargy often resolves with rest, adequate sleep, decreased stress, and good nutrition.[21][22]
This example leads to another key aspect of boredom. As Eastwood, Frischen, Fenske, and Smilek point out, bored people become aware of their difficulty concentrating. As a result, bored people often try to amuse themselves by daydreaming and letting their mind wander. Interestingly, while mind wandering helps people to keep their minds occupied, studies suggest that the more your mind wanders, the more bored you feel. The idea is that you recognize that this daydreaming is meant to occupy your mind, and so you realize that the situation is boring.
If he can maintain his concentration, Goetz intends to continue his own research into understanding the nature of boredom. He wants to measure physiological signs of arousal, which could one day add a new component to wearable health trackers. He’s also interested in investigating whether specific boredom types correspond to different age levels and cultures. “There are many important questions to be answered related to the boredom types,” he says.
“I don’t like to be bored, but without it I couldn’t escape from it. Creativity is the byproduct of escapism.⁣⁣ Inventiveness is the byproduct of laziness.⁣⁣ Productivity is the byproduct of your mom.⁣⁣ Lol. Anyways. ⁣⁣The bored do weird stuff to not be bored.⁣⁣ The lazy invent things like cars so they don’t have to ride horses. ⁣⁣Get bored to get busy.” 

What can you do about boredom? Obviously, there are times when you are stuck. If you are listening to a lecture that you cannot leave, then you just need to find a way to get through it. When you have some control, though, use your understanding of boredom to help you out. If you can, try to do a meditation exercise to lower your arousal level. Also, keep some music handy. Music you enjoy can crowd out distractions in the environment. It can also influence your mood in positive ways to counteract the pain of being bored.  
A 1989 study indicated that an individual's impression of boredom may be influenced by the individual's degree of attention, as a higher acoustic level of distraction from the environment correlated with higher reportings of boredom.[32] Boredom has been studied as being related to drug abuse among teens.[33] Boredom has been proposed as a cause of pathological gambling behavior. A study found results consistent with the hypothesis that pathological gamblers seek stimulation to avoid states of boredom and depression.[34] It has been suggested that boredom has an evolutionary basis that encourages humans to seek out new challenges. It may influence human learning and ingenuity.[35]

When the antiproton was discovered … it sent a wave of ennui through the physics community. Not that its discovery was unimportant, but on the basis of Dirac's theory, everybody expected it. — Roger G. Newton, The Truth of Science, 1997 Chauncey and I were keen enough about our aesthetic solution to the ennui of war to try to proselytize others. He organized discussion groups with the crew; I took volunteers to visit landmarks … — Louis Auchincloss, "Atlantic War," in Authors at Sea, ed. Robert Shenk,  1997 The attendant outside was standing on tennis balls, exercising the soles of her feet, her body swaying back and forth with the ennui of jelly. — Edna O'Brien, New Yorker, 17 June 1991 Thus the days of life are consumed, one by one, without an object beyond the present moment; ever flying from the ennui of that, yet carrying it with us … — Thomas Jefferson, in a letter dated 7 Feb. 1787 Thomas Jefferson: Writings,  1984 the kind of ennui that comes from having too much time on one's hands and too little will to find something productive to do