hi! those are Hindu-Arabic numerals. There's lots of room for more responses to your questions, but these related posts can get you started:

When were Hindu-Arabic numerals adopted in Europe:

• How and when did the arabic numbers took over the roman numbering system in Europe?

• When did Roman numerals stop being used?

• When did Europeans start using Arabic numerals?

• At what point did it seem Western culture switched from "Roman" numerals (I,V,X,etc.) to the more modern, "Arabic-Hindu" numerals (1,2,3,etc.)?

Reasons for adoption:

• Why did Arabian numerals become the dominant numerals in Europe over Roman numerals?

• How did the Arabic numerals become the world standard, essentially, for enumeration?

Other numerals, & adoption elsewhere:

• Friday Free-for-All | January 03, 2014 - casual comments on other numerals

• When and how did Asian countries switch to the use of Arabic numerals? - Japan

• Why is South Asia the only place to use crores and lakhs in its numbering system?