Are bylaws the same thing as an operating agreement?

Not exactly. Bylaws are used by corporations and govern the procedures for voting and other matters. The operating agreement, while having some characteristics of bylaws, is normally more complete and covers matters like buy-sell and dispute resolution between the members. A shareholder agreement (used by a corporation) is essentially the same as an LLC operating agreement. If you are part of a multi-member LLC, you really must speak with an attorney to draft the operating agreement. A good agreement is long and complex (it can be upwards of 50 pages or more depending on the venture) and is much more complicated and substantive than a bylaw.

By-laws are for corporations, Operating Agreements are for LLCs. Operating Agreements tend to be more extensive and discuss matters like contributions to capital, distributions, and tax treatment where by-laws generally do not.

All good points so far. The two are not the same as you asked. The only similarity at a meta level, to some extent, is that they are the "rules of the road" so to speak for the entity. Put another way, its where you look to see how to operate the company. LLC Operating Agreements are more comprehensive so they are like By-Laws plus shareholder agreements combined somewhat. Drafting them is complex if you want to avoid being elliptical and to tailor it to your specific situation so you should hire an attorney.