will the changes we make to the custom settings objects be reflected to production

can we copy records from production to sandbox what is the actual purpose sandbox? do we just test the data in sandbox or can we copy data from sandbox to production?

can we make changes to the custom settings objects in production or shall we do it in sandbox?

1.can we delete apex class from production?

I am creating an action of assigning a task on a particular object using process builder , but the task is not being displayed in the "open activities" related list in the record detail page of that particular object after activating the process , what could be the reason for this?

Thanks 

I am creating an action of assigning a task on a particular object using process builder , but the task is not being displayed in the "open activities" related list in the record detail page of that particular object after activating the process , what could be the reason for this?

Thanks in advance

who can create apex classes and triggers? is it only the system administrator or any other user in an Org.

Thanks in Advance.

 

How Many records can a trigger hold at a time?

How many users can be created using a 'salesforce' user license in a Developer Edition?

I have created a user in developer edition with certain(standard employee) profile with a  'Read only' access on only  one object in the Application , say the object name is 'position'  means this user has no access on other objects in the Application , but when i assign this user a 'CEO' role which is the highest in the role hierarchy , this user is getting Read/write access to the records of the objects on whom the user has no access at all(shown in the 'sharing' option on the object detail page) , this is happening when i am logging in as a system administrator , but when i log in as that particular user , i am able to  see only 'position' tab along with the 'home' tab in the user's home page , what is the difference , do the user actually has the Read/write access to the records of the  other objects as he is high in the hierarchy or it just appears when i log in as a system administrator?can the user access other object records when he/she is logged in with user login credentials(not system administrator) , if Yes , how?
Thanks in advance

while creating  a user  , we select one of the  user license  from the user license drop down list and we assign the user with a profile which will be having a certain license  , now if i want to assign a permission set to that user , the permission set's license should match with which license i.e. with the user's license or the profile's license which we have assigned to that user?

can we make changes to the custom settings objects in production or shall we do it in sandbox?

I am creating an action of assigning a task on a particular object using process builder , but the task is not being displayed in the "open activities" related list in the record detail page of that particular object after activating the process , what could be the reason for this?

Thanks 

How Many records can a trigger hold at a time?

How many users can be created using a 'salesforce' user license in a Developer Edition?

while creating  a user  , we select one of the  user license  from the user license drop down list and we assign the user with a profile which will be having a certain license  , now if i want to assign a permission set to that user , the permission set's license should match with which license i.e. with the user's license or the profile's license which we have assigned to that user?