ACT I - Sets up your story; tells us who your main character is, what their goal is and introduces the main conflict that becomes their obstacle. Also sets the tone and style the movie will take.
TURNING/PLOT/STORY POINT #1 – Is an action or event that comes near the end of Act I (around pages 25-30) and turns the narrative drive of the story into a new direction, kicking it out of the Setup of Act I and into the Confrontation of the Act II. Either the protagonist’s Outer Goal is defined or the means to achieve their Goal become clear and they start on the path toward achieving it.
ACT II – Your main character begins confronting the series of obstacles standing in his/her way. They also reveal more about themselves (backstory & secrets) and what motivates them. They suffer setbacks that test their desire for their goal, often culminating in a “darkest hour” when all seems lost right before Turning Point #2.
MID-POINT – The scene or event halfway through the second act, and therefore halfway through the script, which gives a change in direction to the story. The mid-point functions as a setback, reversal or turning point which sends the character in a new direction, pushes the plot into a higher gear or raises the character’s commitment to another level. It can also be a “lynchpin” that helps connect Turning Point #1 to Turning Point #2.
TURNING/PLOT/STORY POINT #2 – Is an action or event that comes near the end of Act II (around pages 85-90) and turns the narrative drive of the story into a new direction, kicking it out of the Confrontation of the Act II, closer toward the Resolution of Act III and moves things into a “higher gear.” Sometimes it is the “light at the end of the tunnel”: something that gives them new information or inspiration to move beyond the “darkest hour” and push toward the climax.
ACT III – Things pick up speed now as the protagonist moves faster and closer to achieving their goal, putting the final pieces of the plot’s “puzzle” together and racing toward the…
CLIMAX – Your character faces the biggest obstacle of all in a climactic showdown and, in doing so, finally achieves the opportunity to realize his/her Outer Goal.
DENOUEMENT — The “wrap-up” after the climax. No more than 5 pages that quickly tie up the script’s loose ends, i.e., “They lived happily ever after.”

Thanks for this! Quite a very good visual help.
Thanks Marisa, glad it is of some help!
The visual diagram at the top comes from Syd Field’s first screenwriting book (the Grandaddy of them all!), SCREENPLAY.
The rest is my synthesis of general screenwriting principles and experience.