Explanation
Line charts connect individual data points in a view. They provide a simple way to visualize a sequence of values and are useful when you want to see trends over time, or to forecast future values.
Please refer to the images below:

Explanation
A bullet graph is a variation of a bar graph developed to replace dashboard gauges and meters. A bullet graph is useful for comparing the performance of a primary measure to one or more other measures.
Therefore, we need at least 2 measures for creating bullet graphs.

Explanation
Of course! As an example, see below:
1) Using the Sample Superstore data, let's plot a bar chart showing the Sales for each Category:

Observe that we have 3 marks - Each bar in a bar chart is called a mark. Similarly, each point in a scatter plot is also a mark , and so on for all charts.
1 row by 3 columns means that clearly on the y-axis (Sales), we have only a single mark - a single continous axis, but 3 different marks (Technology, Furniture and Office supplies ) on the x-axis.
2) Now let's add subcategory to the view as well (another dimension):

Observe that the number of marks has increased - i.e the number of Bars.
Also, notice we now have 1 row and 17 columns. Simply because 1 row = Sales (on the y-axis), and on the x-axis, we have 17 different columns (i.e product sub categories!!)

Explanation
Yes! To concatenate fields, they must be of same data type. However, there is a workaround which we can use
- Type casting. See below:

Here, State and City are Strings, but Postal Code? Nope. It's an Integer. So we can simply use the STR() function to convert it into a String, and hence the entire equation becomes valid!

Explanation
Bin are a user-defined grouping of numerical data in the data source.
According to the official Tableau documentation: It's sometimes useful to convert a continuous measure (or a numeric dimension) into bins.
Have a look at the following image. When we right click a measure, we get the following options:

However, for a dimension (this is because the of this dimension is a string:

But what if we have a dimension of type NUMBER (NUMERIC DIMENSION)? See below:

We can clearly create bins from dimensions too - they just have to be numeric :)
For more information, please refer to: https://help.tableau.com/current/pro/desktop/en-us/calculations_bins.htm