OSX won't boot properly - Pls help

Hi I'm new to Mac recently my mac is behaving very strangely and i don't understand why this is happening, so anybody who has good knowledge about mac can help or guide me in understanding what the problem is and what should i do.

When i start my mac the apple logo appears then instead of login screen i get this screen and i don't understand what this is and what to do can some one please tell me why am i getting this screen when i start my mac.

Just for your knowledge I'm not pressing any button other then start button of Keyboard, Mouse & Mac.

The funny thing is that it only happens when whole night i don't use my mac & the next day when i start my mac immediately after apple logo this screen appears and stays for 4 to 5 minutes then again login screen appears for me to login to OS X then it works as if there wasn't any problem no matter how many times i restart my mac or start.

Thanks

It appears you're booting the Mac in "verbose" mode. In other words, watching the POST and boot sequence on the screen rather than it being done in the background. This can be useful for trouble shooting but definitely annoying if you're not doing that.

Since you're new to the Mac operating system, follow along and we'll try to turn it off.

Open your Applications folder and then click on Utilities. Look for "terminal.app". Once you find it, click on the terminal application to open it. Once it opens, type in the following information and then press enter:

sudo nvram boot-args=

Now type in the word exit

Restart your Mac to see if the verbose mode has been turned off.

Thanks chscag i really don't understand what you said since I've grown up using pc but any way will try that and see if the problem exist.

Yes thanks chscag the command u told me to enter seems to work, last night i kept my mac shut for the whole night today morning after 8 or 9 hours when i started my mac apple logo screen appeared then login screen appeared.

Thanks for helping me now my mac is not booting in verbose mode.

OK, great. I'm sure that verbose mode was turned on accidentally. Anyway, glad it's working normally now.

Hello again i just started my mac again to surf the net and again i got the same screen so i turned off the main power button which supply electricity to mac then i plug out power cord of mac pressed & hold power button then restarted the mac again but this time i got some another screen i have taken pic from my camera can some one pls tell me what is happening

Please tell me why is my mac behaving this way what should i do?

Go into Recovery and run Repair Disk on your hard drive.

http://support.apple.com/kb/HT4718