What is the difference between genomic selection and GWAS ?

Aspect	Genomic Selection (GS)	Genome-Wide Association Studies (GWAS)
Objective	Predicting breeding values for selection purposes	Identifying genetic variants associated with traits
Scope	Predicts breeding values based on genome-wide marker data	Identifies marker-trait associations across the genome
Marker Use	Utilizes genome-wide marker data for prediction	Utilizes marker-trait associations for association mapping
Sample Size	Requires training population with phenotypic and genotypic data for model calibration	Requires large sample sizes for detecting significant associations
Target Trait	Suitable for traits with moderate to high heritability	Suitable for traits influenced by common genetic variants with moderate to large effects
Precision	Offers high predictive accuracy for traits under selection	Provides information on specific genetic variants associated with traits
Predictive Power	Predicts the genetic merit of individuals for breeding purposes	Identifies genetic variants contributing to phenotypic variation
Application	Widely used in plant and animal breeding programs for genomic selection	Commonly used in genetic studies to dissect the genetic architecture of traits
Validation Requirements	Requires validation in independent populations to assess prediction accuracy	Typically requires replication of significant associations in independent populations
Genetic Architecture	Suitable for traits influenced by many small-effect loci	Suitable for traits influenced by a few large-effect loci or many small-effect loci
Breeding Value Prediction	Predicts the aggregate genetic value of individuals based on marker data	Estimates the effect size and significance of individual markers on trait variation