Incorrect password error when downloading apps on Apple Store

I go to Apple Store, then I login. I try to download app, but it doesn’t work. It needs a password. I put the correct password, but it doesn’t give any response. It says it’s a wrong passport or Apple ID.

[Re-Titled by Moderator]

Original Title: Like I have a trouble in login in downloading apps, my Apple Store is asking again and again about passwords and I have already changed my Apple account password, but it doesn’t works and I am putting correct password then also, it’s asking