How do I explain his line of codes or commands

library(RTextTools)

library(e1701)

dataset <- read.csv("GradeData.csv")

index <-1:nrow(dataset)

testindex <-sample(index, trunc(length(index)*35/100))

testindex

testset <-dataset[testindex, ]

trainingset <-dataset[-testindex,]

summary(testset)

summary(trainingset)

model<-svm(GradeRating ~ .,data=dataset)

print(model)

plot(model, dataset)

model <-svm(GradeRating ~ .,data=trainingset)

plot(model, trainingset)

prediction <-predict(model,testset[,-1])

tab <-table(pred=prediction,true=testset[,1])