difference between <- and = in R with an example

Question

I saw this as a question on datacamp.

(1)

vector <- c("a","b","c","d")
my_list <- list(vec=vector)
my_list

output:

$vec [1]"a" "b" "c" "d"

(2)

vector <- c("a","b","c","d")
my_list <- list(vec<-vector)
my_list

output:

[[1]]
[1] "a" "b" "c" "d"

So, I wondered how different they are and what's the different between <- and = in R. I would highly appreciate any help.