A Production function tells you how much output you can produce for every combination of inputs.

An Isoquant is a curve that shows all possible combinations of input that yield the same output

Example of production function:

(Q = output L= Labor K = Capital)

Q = K + 5L

for the isoquant for example, using the production function above, we want to find which levels of input would yield Q = 20

20 = K + 5L

if K = 5, then L = 3 and if K = 10, then L = 2, your output would still be the same and that's your isoquant.

But for your production function your output can have different values so you'd have multiple isoquant curves and multiple isoquant curves already describe an isoquant map (Isoquant map - shows a number of isoquant curves in a single graph, describing a production function)

Hope my explanation wasn't too confusing...