What is "change" ?

[Xiaoxiao]

Under main account, there is receiving with 4 or 5 addresses and then there is "change" with 3 addresses.

Any difference between the 2?

[shorena]

-snip-
Any difference between the 2?

Nope, change addresses are the same as regular addresses, but Electrum creates them automatically for you. When you want to spend an input (formerly received transaction) you have to spend all if it in the transaction, this is not allways what you want. Sometimes you will want to change less and thus the rest is getting send back to you.

E.g. you get 1 BTC and now want to spend .3 of it. .7 will go to your changeaddress (we ignore the fees here).

Think of it as if you had recieved a lump of gold worth 1 BTC and now want to spend it. Youd have to melt it into two parts. One to keep and one to actually spend.

[pooya87]

Under main account, there is receiving with 4 or 5 addresses and then there is "change" with 3 addresses.

Any difference between the 2?

it is a good way of keeping are your small remaining amounts from previuos payments in one place so your other main addresses wont get crowded

[twister]

Some people prefer to use one address for one transaction and which is why they use change address for the remaining balance after a transactions, if you don't want to use it you can un-check the option "use change address" in preference.

[bitkilo]

-snip-
Any difference between the 2?

Nope, change addresses are the same as regular addresses, but Electrum creates them automatically for you. When you want to spend an input (formerly received transaction) you have to spend all if it in the transaction, this is not allways what you want. Sometimes you will want to change less and thus the rest is getting send back to you.

E.g. you get 1 BTC and now want to spend .3 of it. .7 will go to your changeaddress (we ignore the fees here).

Think of it as if you had recieved a lump of gold worth 1 BTC and now want to spend it. Youd have to melt it into two parts. One to keep and one to actually spend.

Well put Shorena,
It's like paying for a $4 beer with a $50 note you can't just cut off $4 worth and give that to the bartender, you need to give them the whole $50 and they will give you $46 in change.
Bitcoin work the same way.