Cpuinfo

cpuinfo is a handle in the proc filesystem, informing you about the CPU type and features in your system.
Example:

kolossus:~ # cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 3
model name      : Intel(R) Pentium(R) 4 CPU 3.00GHz
stepping        : 3 
cpu MHz         : 2992.966
cache size      : 1024 KB

Hint: For the future, please learn to use hwinfo --cpu instead of cat /proc/cpuinfo. The /proc folder is about to be transitioned to the /sys folder.