Understanding output of rbind function when a list is passed as argument

Question

While using R to practise fundamental matrices questions, I came across the following solution to one of the questions:

l <- list ()

l[[i]] - c for I in 1:5) (i, 1:4)

do.call mat list (rbind, l)

Despite knowing how do.call operates, I tried to generate a matrix using rbind without any preparation, and the results were as follows:

rbind(l)

# [,1] [,2] [,3] [,4] [,5]

Number l, integer 5, integer 5, integer 5, integer 5,

I made an effort to interpret the results from Google, but none of them were helpful. Please assist in making sense of the output.