The CPI is the Consumer Price Index, a measure of the rate of change in the average price of a fixed basket of goods and services purchased by consumers. This is one of the major measures of inflation and, as such, is split into two primary components: CPI and CPI less food & energy. these are pretty much what they sound like.
For January, the CPI-U came in at 0.4% (slightly worse than expected). Meanwhile, the "core" CPI-U came in at a mildly disappointing 0.2%. Energy costs rose 2.1%, but energy service costs declined 0.6%. Looking to February, the Econoday-surveyed analysts are expecting CPI-U to rise another 0.4%, with "core" CPI-U rising at only 0.1%.
With all that in mind, we turn to the US Bureau of Labor Statistics for the CPI Summary. In February, the CPI-U increased by 0.5% (missing expectations), and the "core" CPI-U rose 0.2% (also missing expectations). Energy rose 3.4% for the month (with gasoline up 4.7% and fuel oil up 5.8%), and food rose 0.6%.
 I believe I made my weekly vitriolic observations about "core" inflation measures yesterday when I discussed the PPI. In order to spare everyone, I'll refrain from repeating myself.