in my garden i have 6 lights each one have a switch, last week i connect all the lights to one switch so all the 6 lights will turn on with one switch, but some time i don't need all the 6 lights on, and other time i want them all on. so, is there a way to have a switch for each light and a master switch for all the light. (for example:if tow light on, and than i click on the master switch all the other 4 lights will turn on and if i click on it again all the 6 will turn off) (another example:if all the light on and i turn off 3 of them then use the master switch the other 3 will turn off) is that possible?
You could use smart switches and have a lot of versatility... but you can also do it with manual switches easy enough.
At the first switch point, you have the "master switch". You bring in always-hot and neutral. Pass through neutral, connect always-hot to the switch, and switched-hot to the other side of the switch.
Then at the second switch point, you have 6 switches. Switched-hot goes to each of the switches. Then branch-switched-hot comes off the other side of the switch for each of the six branches.
In this diagram, black=always hot, red=master-switched-hot, and all other colors are branch switched hots. Grounds not shown because, enough.
Not really attainable without buying and building a relay panel, or using some sort of programmable switch control system, and even then if you are not familiar with programming these, it's not easy.
More attainable is to use your Master switch switch by putting it ahead of the other 6, then use the other 6 switches down stream to select WHICH of the lights you want to come on and off with the Master.
There are ways to achieve what you mention, but it is not as simple as placement of switches between power source and loads.
One switch could feed six switches, which in turn feed six lights. When the master switch is on, the other switches are operable. When the master switch is off, there is no power.
You could use a digital switch that can handle 'scenes', which is to say it can be programmed to turn on or off (or dim) different combinations of the six lights, which would then be selectable with push buttons.
An [expensive] example of this kind of switch would be the [Crestron CLSI-C6MRF1:
This still does not allow the master switch to swap the state of the bulbs, but some programmable systems may permit this. In such a case you may need to install a controller unit or hub with potentially wireless switches and hidden switching/dimming units for each of the six lights.
This kind of installation is of the type that might be designed and carried out by a home automation professional.