What's the difference between 은 and 는 next to a word in Korean?

은/는 is subject particle and it varies to syllables in a subject noun. For example if the noun ends with vowel the particle forms 는. But if it ends with consonant (or let's say Batchim: 받침) the particle forms 은.

e.g.

저는 (I am)

여기는 (Here is)

저기는 (there is)

이것은(this is)

저것은(that is)

제 이름은 (my name is)

1. a

2. b

3. d

4. d

5. b

6. b

7.b

8. a

9. d

10. d