The House has a reputation of being much more contentious and impulsive when it comes to legislation.  By comparison, it is fairly easy to be elected to the House, which means you have won a congressional district vote vs. a Senate seat which is a statewide vote.  So Senators, by definition, usually have to be more moderate than Representatives in order to get elected.

The House will often vote for controversial policies such as abortion limits or banning flag burning, knowing full well they can make such votes without it having a chance to pass the Senate.  So they can posture and throw red meat to the crowds in their districts without actually having to accomplish anything.

I'm not going to look at the modern political differences, I'm going to stick to basics.

As mentioned earlier, the main similarity between the two houses is they serve the same purpose. They both exist to create legislation in our nation. In addition they both have the ability to create bills, and all bills must go through both houses to become law (with some exceptions, but this is meant to be the general course by which a bill becomes a law).

The differences are in the terms and size of the two houses with Representatives serving in the House for 2 years and Senators for six years. There are 435 representatives in the house, a number based on state population. There are 100 Senators, a number based on two senators per state regardless of size or population. Another important difference is that monetary or economic bills must be created in the house. In this way the house holds the purse strings of the nation.

Hope this helps!

The two bodies could not be more dissimilar. Senators are elected for six years, Representatives for two; the minimum age for Senators (30) is five years older than that for Representatives (25). The Senate is much more open to debate than the House. Filibusters, attempts to kill bills by talking continuously, only occur on the floor of the Senate. Riders or amendments to bills in the Senate may take any form and need not be germane to the original bill.  All debate on the floor of the Senate is done after reports from committees.

The House requires that all riders to bills be germane to the bill under debate. The House frequently adjourns and reconvenes as the Committee of the Whole House for the State of the Union. When so sitting, the Speaker normally steps down from his seat, and can engage in debate on the floor. The committee rises and reconvenes only for purposes of voting, not debate. When votes are taken, the Speaker has a vote as does every other member.

The President of the Senate is the Vice President of the United States; however he is not a member of the Senate and may note debate. He may only vote in the event of a tie.

The cynic in me wants to say that the major similarity between both is that the only significant interest of the parties working in both is to get re-elected.  But there are certainly times where some representatives appear to act in the interests of their constituents.  So that they can be re-elected...

But structurally there are similar rules about the passage of and debate of bills that go through each branch of the legislature.  You can also look at the way that bills are really worked on both in committees and in the aftermath of passage when the rulebooks are written that add intricacy and all kinds of details to the way a bill is enacted that weren't always in them at the start or even at their passage.

The major similarity between the Senate and the House of Representatives is that both houses' main job is to legislate -- to create laws for the federal government.  Both houses are also (since the 1910s) directly elected by the people.

The differences between the House and Senate are important.  The Senate was meant by the Framers to be the more deliberative house, less controlled by the people.  Therefore, there are fewer senators, and they are elected for longer terms.  They are also elected by their whole state as opposed to by districts.

In practice today, the major difference between the House and Senate is that the Senate tends to be more moderate.  They are elected by larger, more diverse districts.  The rules of the Senate also allow one senator to have a great deal of power to stop legislation.  A group of 41 senators has the power to stop anything from happening in the Senate.  Therefore, it is much harder to get relatively radical bills through the Senate.