In the name of Allah the most Gracious and the Most Merciful. Holy Quran is the last book of Allah, revealed on our beloved last Prophet Muhammad (ﷺ). As Muslims, we read Quran and in Quran, there are some symbols that represent some meaning and we must have to obey them. If we will not obey it then, the meaning of the verse changes. If you know and understand and still do these mistakes then don't do it, Fear Allah. But if you don't know then Indeed Allah is forgiving and merciful.
The first symbol is "Small Mim" ( looks like Mim ). Whenever you find this sign in Quran while reading it. You must have to STOP on this 'Small Mim'. If you will not stop, the meaning of the verse changes. So we must have to stop on it.
The second symbol is "Lam Alif", whenever you find this symbol in Quran. You don't have to stop but CONTINUE to read the whole verse.
The three-doted symbol means that you should have to stop either at one or second. Remember the three dots always come in the group ( means three dots at the starting of the word and three dots at the end of a word ), and you should have to stop either at first or a second.
Another sign is called "Sa'd", which means KEEP GOING. You should not stop and keep going and read the whole verse.
Another symbol is called "K'l", which means BETTER TO STOP.
The symbol "Jim", whenever you find this symbol in Quran. At that, you can EITHER STOP or CONTINUE READING.
Another symbol that represents "Sujood", or "Prostration", If you find that symbol after the end of the ayah, whenever you read ayah and you found the sign of prostration, you must have to do sujood or prostration.
The another "Mim", was somehow different from 'Small mim'. It always comes between the word. You should have to ignore the 'Nun' or 'Ba' and recite the word by joining the previous letter with 'Mim'.
Another symbol "Alif", comes in Quran many times. Whenever you found it in the letter, you should have to shortly extend that letter.
The symbol "Senn" ( Sakta ), means that SMALL PAUSE. You should have to pause for a while and then continue to keep reading.
Another symbol is called "Extendary Ma'D" if you found this on any letter. You should have to EXTEND that letter for a long.
The sign of the end of the Quarter of the chapter or Juz. It is divided into eight quarters and the end of each quarter. You will see the sign of Juz as shown.