Civil and criminal trials are conducted in much the same way.
The attorney for the plaintiff (in a civil case) or the prosecuting attorney (in a criminal case) will generally begin with a short opening statement. The defendant's lawyer may then make a similar opening statement, or may wait until after the plaintiff's case has been fully presented, or not make one at all.
The opening statements tell you what the opposing party's claim the facts are, and they outline the evidence by which the parties expect to prove what they say are the facts.
Remember: The opening statements are not themselves evidence; they are only the parties' respective versions of the facts as they claim them to be, which must be proved by evidence.
Evidence is testimony or things (exhibits) which relate to a fact in dispute. Testimony is statements made by a witness under oath at the trial. An exhibit is a physical article, such as a document, a weapon, and a photograph, introduced at the trial to be considered by the jury in determining the facts of the case.
Sometimes the testimony of a witness will have been given outside the courtroom and is read to the jury. The record of that testimony is called a deposition. Or the testimony may have been given at a different trial, in which case the written record is called a transcript. Sometimes videotaped depositions are allowed in certain circumstances.