Compiler techniques are methods used in the design and implementation of compilers, which are programs that translate high-level programming languages into machine code. These techniques include lexical analysis, syntax analysis, semantic analysis, optimization, and code generation. Each step plays a crucial role in ensuring that the source code is correctly interpreted and efficiently executed by the computer. One important aspect of compiler techniques is the use of data structures, such as abstract syntax trees and symbol tables, to manage information about the program being compiled. Additionally, techniques like dead code elimination and loop optimization help improve the performance of the generated machine code, making programs run faster and use fewer resources.