Nancy Pelosi announced rather recently that there is an impeachment inquiry on Trump's contact with the Ukranian President in regards to investigating 2020 Presidential Candidate Joe Biden.
Before people get too excited and think that this means Trump will be out of office in no time since the word "impeachment" was used, let's talk about what impeachment really is.
By definition, impeachment is "a charge of misconduct made against the holder of a public office". In simpler terms, the word impeachment means to bring charges against someone in a public office. In this specific case, it is the President. So, how do they get removed from office?
First, there has to be some sort of reason to impeach the President (or any government official in that matter). Congress begins to investigate whatever situation has occurred that they believe could be an offense worth impeachment. After that, The House of Representatives must proposed impeachment and it must be decided on by a simple majority on whether or not they will bring these allegations to light. Once decided on, the Senate then tries the person in question. If found guilty, and it is believed that the actions they were found guilty of putting national security at risk in any way, the person can therefore be removed from office.
So, it sounds quite complicated, but it really isn't. They vote to see if they should formally investigate an instance caused or in association with someone holding public office, and if they are found guilty, they have a chance of being removed from office. However, they don't always get removed.
For example, three Presidents have been impeached-- Andrew Johnson, Richard Nixon, and Bill Clinton. Although Nixon resigned before he could be removed from office, the other two Presidents carried out their term even though they technically were guilty of what they had committed.
Andrew Johnson was brought to trial for firing a cabinet member without approval from Congress. Bill Clinton was brought to trial for his relations with Monica Lewinsky and perjury that they both had committed. However, both these cases we acquitted which allowed them to stay in office.
So, although Trump has formally began the impeachment process, that does not guarantee his removal from office. Most Americans though are uneducated on the entire process and believe that impeachment means whoever the charges are against will be kicked out of office. Hopefully this sheds light on what is currently happening in easy to understand terms.