A relational symbol denoting "much less than" or asymptotic dominance in analysis and computational complexity.
Examples
Much less than relationship between numbers
1 \ll 1000000
Order of magnitude comparison
\text{If } x \ll y \text{, then } \frac{x}{y} \approx 0
Asymptotic behavior
\text{For } n \ll N\text{, the algorithm runs in } O(n) \text{ time}