Sweeping an address allows the client to send all the funds in the address to an address generated by the Electrum seed. You would need to remember the seed and the change will be sent to an address generated by the seed. The new address would then be covered by the seed.
Importing an address makes the client import the address directly, without doing anything to it. When you want to spend the coins, the inputs would be from the imported address and the change will be sent back to the origin. You need to make a backup of your own private key.
Thank you very mach.
Did I have have to make transaction from sweeping address to one address in my wallet or Elektrum make this transaction automatically.