Entropy is a measure of number of options a system has.

what do I mean by options ,let me clear it with an example of coins  . Lets take 3 coins and give them name coin A  ,coin B  ,coin C. If i tell you, two of the three coins showing heads and one showing tail,then there are three possibilities (options)

1. Coin A and Coin B showing heads  ,coin C showing tail

2)Coin B and coin C showing heads  ,coin A showing tail

3)coin C and coin A showing heads  ,coin B showing tail.

So there are three possibilities (options).

Now if I tell you all of them showing heads  ,there is just one possibility (option)  ,that is,

Coin A is showing head  ,coin B showing head  ,coin C showing head. Similarly if i tell you  ,of the three coins  ,only one is showing head  ,there are three possibilities(think about it yourself).

The more the possibilities(options)  ,the more the entropy,in the 2nd case entropy is minimum (only one possibility).

Now let me connect this idea with actual physical systems  ,lets take the famous example  ,gas molecules in a box. A system of gas molecules in a box in equilibrium is going to have some definite entropy.

Here in this example by possibilities or options we mean possible position and momentum the molecules of gas can have. What will happen if we double the volume of the box,entropy increase or decrease?

When we double the volume the possible positions that the molecules in the gas can take increase,the molecules now can explore larger volume of space  . Possibilities increases so thus entropy. Similarly if we heat the gas keeping volume constant  ,the molecules going to vibrate and move faster  ,so the entropy increases  ,possible momentums the molecules can have increase .

Think about entropy  ,as a measure of possibilities or options the system has  , the more the options the more the entropy.

Entropy is a measure of a number of options a system has.

What do I mean by options?

Let me clear it with an example of coins. Let's take 3 coins and give them name coin A, coin B, coin C. If I tell you, two of the three coins showing heads and one showing tail, then there are three possibilities (options)

1. Coin A and Coin B showing heads, coin C showing tail

2)Coin B and coin C showing heads, coin A showing tail

3)coin C and coin A showing heads, coin B showing the tail.

So there are three possibilities (options).

Now if I tell you all of them showing heads, there is just one possibility (option), that is,

Coin A is showing head, coin B showing head, coin C showing head. Similarly, if I tell you, of the three coins, only one is showing head, there are three possibilities(think about it yourself).

The more the possibilities(options), the more the entropy, in the 2nd case entropy is minimum (only one possibility).

Now let me connect this idea with actual physical systems, let's take the famous example, gas molecules in a box. A system of gas molecules in a box in equilibrium is going to have some definite entropy.

Here in this example by possibilities or options, we mean possible position and momentum the molecules of gas can have. What will happen if we double the volume of the box, entropy increase or decrease?

When we double the volume the possible positions that the molecules in the gas can take the increase, the molecules now can explore a larger volume of space. Possibilities increase so thus entropy. Similarly, if we heat the gas keeping volume constant, the molecules going to vibrate and move faster, so the entropy increases, possible momentums the molecules can have increased.

Think about entropy, as a measure of possibilities or options the system has, the more the options the more the entropy.

Entropy is a measure of number of options a system has.

what do I mean by options ,let me clear it with an example of coins . Lets take 3 coins and give them name coin A ,coin B ,coin C. If i tell you, two of the three coins showing heads and one showing tail,then there are three possibilities (options)

1. Coin A and Coin B showing heads ,coin C showing tail

2)Coin B and coin C showing heads ,coin A showing tail

3)coin C and coin A showing heads ,coin B showing tail.

So there are three possibilities (options).

Now if I tell you all of them showing heads ,there is just one possibility (option) ,that is,

Coin A is showing head ,coin B showing head ,coin C showing head. Similarly if i tell you ,of the three coins ,only one is showing head ,there are three possibilities(think about it yourself).

The more the possibilities(options) ,the more the entropy,in the 2nd case entropy is minimum (only one possibility).

Now let me connect this idea with actual physical systems ,lets take the famous example ,gas molecules in a box. A system of gas molecules in a box in equilibrium is going to have some definite entropy.

Here in this example by possibilities or options we mean possible position and momentum the molecules of gas can have. What will happen if we double the volume of the box,entropy increase or decrease?

When we double the volume the possible positions that the molecules in the gas can take increase,the molecules now can explore larger volume of space . Possibilities increases so thus entropy. Similarly if we heat the gas keeping volume constant ,the molecules going to vibrate and move faster ,so the entropy increases ,possible momentums the molecules can have increase .

Think about entropy ,as a measure of possibilities or options the system has , the more the options the more the entropy.

Entropy is a measure of number of options a system has.

what do I mean by options ,let me clear it with an example of coins . Lets take 3 coins and give them name coin A ,coin B ,coin C. If i tell you, two of the three coins showing heads and one showing tail,then there are three possibilities (options)

1. Coin A and Coin B showing heads ,coin C showing tail

2)Coin B and coin C showing heads ,coin A showing tail

3)coin C and coin A showing heads ,coin B showing tail.

So there are three possibilities (options).

Now if I tell you all of them showing heads ,there is just one possibility (option) ,that is,

Coin A is showing head ,coin B showing head ,coin C showing head. Similarly if i tell you ,of the three coins ,only one is showing head ,there are three possibilities(think about it yourself).

The more the possibilities(options) ,the more the entropy,in the 2nd case entropy is minimum (only one possibility).

Now let me connect this idea with actual physical systems ,lets take the famous example ,gas molecules in a box. A system of gas molecules in a box in equilibrium is going to have some definite entropy.

Here in this example by possibilities or options we mean possible position and momentum the molecules of gas can have. What will happen if we double the volume of the box,entropy increase or decrease?

When we double the volume the possible positions that the molecules in the gas can take increase,the molecules now can explore larger volume of space . Possibilities increases so thus entropy. Similarly if we heat the gas keeping volume constant ,the molecules going to vibrate and move faster ,so the entropy increases ,possible momentums the molecules can have increase .

Think about entropy ,as a measure of possibilities or options the system has , the more the options the more the entropy.