Define the terms SPI, EV, PV, VAC, BAC,EAC ,CV,SV,ETC in cost management?

we can add to the nice answer from Mahmoud Basha the following equations and tips: EV = the estimated value of the outcomes of the project during the execution PV = the planned value of the outcomes of the project during the execution BAC = planned total budget SV = EV - PV CV= EV - AC SPI = EV / PV CPI = EV / AC VAC = BAC - EAC ETC = this is a new estimate based on forecasting EAC = AC+ETC...
EAC forecast for ETC at new estimate EAC = AC+BAC-EV......
EAC forecast for ETC work performed at the budgeted rate EAC = BAC/ CPI .......EAC forecast for work performed at the percent CPI EAC =AC+(BAC-EV) /(CPI*SPI).....EAC forecast for ETC work considering both SPI and CPI

Thanks to ASARUDEEN for his valuable question and to both MAHMOUD and YASSER for their valuable detailed answers concerning the definitions of the cost management's abbreviations the only thing that I can add is the efficiency factor which is a very great indicator to be used for monitoring and controlling the project by using the EANED VALUE method The efficiency factor (EFFIC)= SI*CI.
Thanks for you all Best regards Eng,Ali Harin

SPI or Schedule performance index, is the ratio between earned value and planned value EV/PV), and could be interpreted as "We are now progressing at "---" % of the rate originally planned.
EV - Earned value, as of today what's the estimated value of the work actually completed.
PV - Planned value, as of today, what's teh estimated value of the work planned to be done.
VAC - Variance at completion., as of today, how much over or under the budget we expect at the end of the project.
BAC - budget at completion.How much did we budget for the total project to be done.
EAC - Estimated value to complete, what do we currently expect the total project to cost.
CV - Cost variance, how much we are over or under the budget today SV - Schedule variance, how much we are behind or ahead of the schedule.
ETC - estimate to complete, from this point on, how much do we expect more to finish the project.

Very nice Mr.basha.
Thanks for your participantion to share your knowledge