Chakras are certain areas of the body where energy collects before moving to the next area. The best and easiest example I have seen was presented by a children's television show, "Avatar, the Last Airbender" in which the main character of the show, a young monk, is learning about the chakras and describes them as "pools of spiraling energy in our bodies".
A youtube video will be linked that was edited down to about 10 minutes of the episode where the chakras are explained and I will make a basic and short list based off of this same source to go along with the link, for convenience and time's sake, as there is a trove of information on the subject of each and every chakra and research can be done easily and independently.
The chakras allow the energy to move around in our body and are all connected, so when it comes to doing the work of clearing blocked energy from our chakras, we may find ourselves unblocking one at a time and having to unblock the next one and the one after that until the stagnant energy has been able to move entire through and out of our body.
The eastern tradition of yoga teaches us that there are seven main chakras, but for those of us who know our bodies well or have worked with eastern healing like acupuncture, we know that there are countless more than the seven main ones that travel up and down the center of the body. The hands and feet are great examples as they can be felt and are very present, however they are not considered to be part of the seven main ones.
The seven main chakras, their colors and purposes are as follows;
Muladhara (red): Root Chakra - This is the chakra that deals with our survival instinct and more animalistic aspects of our life, and relates to the basic needs of the human body. It can be blocked by fear, paranoia, or getting stuck in "panic" mode and not trusting that the universe will take care of us.
Svadhishthana (orange): Sacral Chakra - deals with the sexual and "pleasure" aspects of our lives, and it can be blocked by feelings of guilt or lack of control in this aspect such as addiction to said pleasures.
Manipura (yellow): Solar Plexus Chakra - this chakra deals with our willpower, this is the central source of energy that feeds the rest of the chakras, this is the one that connects the "as above" with the "so below", an it is blocked by shame and feelings of unworthiness.
Anahata (green): Heart Chakra - relates to love, passion and who we truly are, our "true colors", this one is blocked by grief or by not allowing ourselves to be the person we know we are.
Vishuddha (blue): Throat Chakra - related to our truth and how we communicate our message, this one is blocked by lies, the ones we tell others, rather than the aforementioned illusion of the lies we tell ourselves.
Ajna (Indigo): Third Eye Chakra - related to the intuition, and clairvoyance, this chakra is blocked by the illusions we create for ourselves
Sahasrara (purple): Crown Chakra - related to cosmic energy, and our connection to source, this chakra is blocked by our earthy attachments as it takes us away from our divine and complete selves
For those who are taking a Kabbalah approach to magick, the main chakras are seen as five central ones with three on the left and another three on the right, for a total of eleven instead of seven, with similarities in color and correspondence but bearing some differences and ancient hebrew names rather than sanskrit.
This chakra system is more complex and will be added in a different section in the near future to keep this section as basic and simple as possible for those who are new to the subject.