Interpreting Grid Template Codes

grid-template-columns: 1fr;
grid-template-rows: 50px auto 1fr auto;

Could I have someone check my interpretation of the above lines of code?
For the columns - we have a single column that occupies the entire width of the container
For the rows - top row is 50px tall
next down fits to the size of the content
next down is what is left over after other 3 row conditions have been satisfied
bottom row fits to the size of the content

So have I got this right?