What are differences among meaning of healing charka, tuning charka & opening charka?

About chakras, there are many distorted images. Chakra is a centrum in a  body, join a man with  spiritual levels. Healing chakra is I think only a joke.

In chakras are great spiritual powers, called siddhis. But for obtain a siddhi you must open chakra. And it  can take for many years.
In current westërn texts is strictly recommended meditate about all chakras. But, in eastern countrees are two ways. There about all chakras do a meditation only yogis, who want to awake the Serpent power, Kundalini and terminate the cycle of lifes, to that calculated lives in a spiritual worlds too.
Yogis who wish to obtain a supernatural powers, and another life in a spiritual worlds do meditation only on a one chakra. Mostly the chakra Anahata for a many years. Only this way awaken in the chakra hidden powers and powers of the lower chakras are then assigned themselves.
Several texts recomended concentartion about the chakra Ajna only. But, there is a great danger of self-destruction the yogi, who done it.

For the awakening the Anahata chakra may be used the follow the breath before a bedtime. Very accelerate the achievement of this.

Good books about Chakras are Shiva samita, Sat chakra nirupana and by A. Avalon, The serpent power.

A similar procedure is in Chinese Taoist alchemy, see you
The secret of the Golden flower. But there is chakra Ajna called "Heavenly Heart and Anahata "Fleshly heart".
The Secret of the Golden Flower  
There is a process of concentration of mind for about three months to Ajna chakra and then transfer the attention to chakra anahata with monitoring breath.

This way awake  powers hidden in the chakra.

See you also the path of Alchemy, for example "The book of Lambspring". (On Levity .com alchemy)
Figure III In the Body there is Soul and Spirit.

In the ancient spiritual teachings is the spirit between the eyebrows, Ajna chakra in yoga
and soul in the place of Anahata chakra.

All quoted texts are freely on the net mostly in pdf format.

Another practices with chakras are useless

thanks for explanation.

Chakras are never completely closed  or shut down because they are contributing to your body 's life.
However they may be semi closed,inactive or in need of energy because of the certain issues you are facing in life which are related to that chakra.
Every chakra is connected to a gland .
Also every chakra has some spiritual purpose  like solar plexus is all about your gut feeling ,willingness  and throat chakra is about your expression etc.

When you have any spiritual or physical problem the relevant  chakra gets clogged or dirty and need healing .Healing the chakras make you feel the difference .

These chakras can be completely opened by  various methods.Opening the chakras don't guarantee healing too because healing is supposed to be  a daily procedure and its like spiritual food your body needs to function properly.Your chakras respond to your thoughts and actions.  
Healing can be done through breathing and yoga etc.

Hope this helps.