No, open source[1] and free software[2] are the same thing. The only difference is in philosophy of advocacy - the open source movement branched off from the free software movement because they wanted to emphasize the practical benefits rather than the ethical aspects (user freedom).
If you look at the definitions I linked to, you'll see that they are very similar to each other and both involve a lot more than "just means you can view the code".
In fact, the very first sentence of the introduction explicitly rejects your proposed definition: "Open source doesn't just mean access to the source code."
[1] https://opensource.org/osd
[2] https://www.gnu.org/philosophy/free-sw.html